By day Vishal Vora is a college lecturer but, once home, he is that most modern phenomenon: an eBayer. His kitchen units, his last four cars, even his floorboards have been bought via the online auction site and the destinations of his family holidays are dictated by the location of the latest purchase he has to collect. He reckons he has spent £20,000 in the past 10 years, but this amiable relationship is now to end in court over a £160 iPhone. Vora, 32, from London, is the latest Observer reader to have found that eBay protects buyers at the expense of sellers and that a long, unblemished record can count for nothing when a transaction goes wrong.

The problems began in September when Vora sold his wife's iPhone4 to an online bidder. "The weight on our Post Office receipt confirms that the phone must have been in the box when it was dispatched, yet the buyer insisted it arrived empty," he says.

Instead of investigating, eBay took £17 from Vora's PayPal account and used it towards refunding the buyer. The balance came from eBay and Vora has since received regular demands from debt collectors to recoup the entire sum. Both his eBay and PayPal accounts have been blocked, even though he is formally disputing the claim.

"They never even asked the buyer to return the packaging as evidence," says Vora. "I have a letter from the Post Office confirming that the weight of the parcel did correspond with an iPhone, yet eBay didn't even perform this most basic investigation before finding against me."

The unusual aspect of Vora's case is he has made the site his first port of call for every type of purchase. "The entire contents of my flat have been bought on eBay, even the kitchen sink," he says.

He searches out items he needs and plans his holidays round the places he has to visit to collect them. His longest trip was from London to Cornwall to collect a crate of vintage crockery and his most expensive to Lancashire for a £2,000 car. "Before we had the baby, most weekends were spent driving up and down the country to collect items," he says. "My wife is resigned to it and has bought a Michelin pub guide so we can build in a nice lunch on the way."

What began as a thrifty exercise for an impoverished student became a lifestyle. "I love the thrill of the chase and the people you meet along the way," he says. "One seller I'd bought an Apple Mac from had just gone through a divorce and detained me for about an hour to talk it through before I could politely extract myself."

He also regards it as an important gesture towards green living. "Most people, when they want a new washing machine go to John Lewis, but why cause new goods to be made when perfectly good ones are available secondhand?"

Until now, the few hitches Vora encountered with transactions had been swiftly resolved between buyer and seller. This is the first time he's experienced eBay's customer resolution service and, he says, he has been shocked by its incompetence. "In December 2013 I was told in writing that I'd be given a final decision in October 2013!"

With debt collectors still in pursuit, Vora began legal proceedings against eBay to recover his money through the small claims court. Ebay initially insisted it had a strong defence and would contest the case. However, shortly after The Observer raised Vora's plight with the press office, it backed down and paid him the cost of the iPhone plus the £17 it removed from his PayPal account and £25 court costs. "We took steps to investigate, including looking at additional information provided by Mr Vora, but we let ourselves down by not providing a full explanation after concluding our investigation," says a spokesman.

Quite what this "investigation" turned up remains a mystery, since eBay has refused to allow Vora to see its "strong defence", and he has now made an application under the Data Protection Act to view it. Ebay has 40 days to respond.

The company says it is taking steps to change its policy when buyers and sellers provide conflicting evidence, although it declines to specify how.

In the meantime, Vora intends to issue new court proceedings to claim compensation for the hours he has spent fighting his case. "Ebay's user agreement states that it shall not be held liable for any losses which 'are not reasonably foreseen by us'," he says. "It will be interesting to let a judge decide whether eBay's conduct has been reasonable."

Vora hopes that his stance will encourage others to fight the arbitrary decisions of monoliths, but his experience has not encouraged him to return to conventional shopping. "This weekend our cafetiere glass broke – and a replacement costs £14. But, after a quick search, I picked up a beautiful limited edition cafetiere for £3," he says. "But, even for me, there remain some things that can't be bought on eBay – I do still visit my high street for a hair cut!"