Easton James and wife Cecilia had to cut short a holiday to Malaysia four months ago to accompany their eight-year-old grandson home, after he had an emergency appendectomy. Credit:Eddie Jim "Ever since it's been non-stop emails ... and about 10 phone calls, each time to a different person," James says. Just 24 hours after I advocated for them, QBE apologised for the internal error and agreed to pay. The insurer also says it is reviewing its claims processes as a result. Common knock-back 1: "Oh, you actually think you can claim on that?" I'm starting with the "automatic" insurance often offered domestically that reimburses nose-bleed car hire excesses (and saves you buying the rental company's extortionate insurance) … if it's worth the paper it's fine-printed on.

Reader Barry hired a car using his credit card so "foolishly" thought the $3000 excess would be covered. No doubt noting he hadn't bought their insurance, at the end of the holiday the car hire company stung him for the full amount because of a "very small ding that had not been noted or seen when we picked it up". "The consumer mavens we contacted [at the time] were all helpful but said don't waste your time pursing free credit card insurance," Barry said. Blanket exclusions can include vehicles other than sedans or stationwagons (so not 4WDs, hatchbacks or campervans) and – somewhat unbelievably – the card insurance may kick in only if you've signed up for all the car hire company's insurance, which defeats the purpose! But in the end, it was a good outcome for Barry and his family: "We fought pretty hard and got the $3000 refunded." Common knock-back 2: "That was a pre-existing condition"

Cheryl booked a trip to Vietnam last year with her 20-year-old grandson, but the week before they departed, she was diagnosed with life-threatening blood clots in the lung. "I placed my claim together with all invoices required plus a letter from my specialist stating clearly that there was no previous condition which led to this event and that the illness was 'unprovoked'," she said. The insurer requested the previous two years of medical records plus a letter from Cheryl's GP to confirm no previous illness … plus more letters from the GP. "The person contracted by the insurer to settle the claim was honest enough to say they were looking for something that would indicate a pre-existing condition so they could refuse the claim," she said. Only after four months, getting angry and threatening to involve the press was Cheryl paid. (Note this was a standalone policy, which is similar to the card version.)

Common knock-back 3: "You didn't pay for it right" Different cards and insurers have different eligibility criteria for complimentary cover – and you sure as heck need to know them. Note it's always per person. But sometimes it's as broad as a certain spend, on flights, accommodation or other holiday costs and others, it's only flights that trigger cover (you might even need to explicitly, in advance, notify your bank you want it). Renee is currently fighting such an issue. Her husband contracted viral pneumonia shortly before a trip to Kangaroo Island and the Barossa – and the insurer is refusing to cover the cancellation as she paid the accommodation on the card but booked the flights on points (sufficient with some policies). "They say that in the fine print it says that you have to book your flight on the credit card to be eligible – it's not on the website," she says. "The annoying part is that I did check with the bank and nothing was mentioned and they refuse to get involved as they say it is the insurer's problem."

Common knock-back 4: "We don't cover mental illnesses [or even non-mental illnesses]" Money has been covering the extortionate pricing of all sorts of insurance by those who have experienced a mental illness. And for travel insurance of any kind, there is often a blanket exclusion. But reader Frank has encountered a devastating variation of this. "I booked a retirement holiday for my wife and myself to the UK just over four years ago, using the card, but my wife was diagnosed with Alzheimer's disease so, of course, I cancelled and applied for travel insurance," he says. "I was told anyone developing a 'mental illness' at any time before or during the period of insurance renders the entire policy void. Alzheimer's is a neurological illness, not a mental one as such."

* All names have been changed to protect sensitive medical information. Common knock-back 5: 'We'll stall until you give up, especially if the claim is small' Daniel had received multiple demands for the same information over a few months but "got the refund soon after I informed the insurance company that I was going to report these multiple demands to the police as harassment", Daniel says. Then there's Cheryl's insight. "[My travel agent said] this type of delaying action is a common occurrence … they were surprised that I got mine paid so quickly as the average anecdotally was six to eight months, if at all," she says. Meanwhile, a doctor who offered to deal directly with an insurance company to recoup the cost of a pre-approved treatment told me: "It was a long and arduous process to extract any payment … [including] hours on hold on numerous occasions." This was over a claim worth less than $600 in total.

And that speaks to a disturbing pattern: most of the delayed or stalled claims about which readers contacted me were small. The type of amount most people would write off once the process becomes too difficult (being aware that card insurance usually has steeper excesses than the standalone equivalents). Nicole Pedersen-McKinnon is a commentator and educator who presents her Smart Money Start, fun financial literacy incursion, in high schools around Australia. Follow Nicole on Facebook at Nicole Pedersen-McKinnon Money.