Reports that recipients of food bank parcels are returning products that need to be heated up came as no surprise to me. Neither did the news that various energy companies were putting their prices up, again by an average of over 9%. Gas prices and train fares seem to be the two commodities for modern British life that base their prices on a whim, or numbers plucked out of thin air, without a thought to the real cost to those for whom those price hikes mean unimaginable sacrifices in their day to day lives.

I don't imagine the chief executives of any of the big six called before MPs on Tuesday has ever had to unplug their fridge because they simply can't afford to run it, or wrap their toddler in a fleece all-in-one and a jumper and a dressing gown of an evening.

It wasn't too long ago myself that I was sitting with my back to my front door, hissing at my toddler to be quiet because there was a man on the other side of it hammering with his fist. I owed Eon £390 in unpaid electricity bills, and they were shouting that they knew I was in there. Every new morning brought red-topped letters, final demands and pairs of men peering through the windows – but as I told them time and again, I couldn't give them what I didn't have.

I couldn't take advantage of the "cheaper bills if you pay by direct debit", because my finances were so chaotic that the direct debits often bounced, leaving me with a £25 charge from my bank and a £12 late fee from the energy company for my troubles. If you haven't got a tenner to get them off your back for a week, you certainly don't have an additional £37 for charges.

I was unemployed, applying for every job that I came across, and mistake after mistake with housing benefit payments meant that I was struggling to get by. The £10 a week food shop has been well documented by now, but I don't really talk about the Christmas day that I sent my son to his father's house to spare him the misery of yet another day in a freezing cold flat, with no television to entertain us, no tree, no presents and nothing that even slightly resembled a Christmas dinner. The furniture was parked in front of the radiators because I didn't use them anyway, and I slept in the kitchen-cum-living room, because it was the warmest place in the house. Some days I barely moved from the day-bed, sitting applying for jobs curled up in my duvet, with Small Boy playing with his toy cars beside me.

Eventually, I was told by one of the men hammering on the door that I would be put on a key meter, another bitter irony, as those with the least money pay the highest rates and tariffs for their gas and electricity.

Sitting at my desk now, in a pair of jumpers rather than turn the heating on, old habits die hard. I work these days and have an income, but I still only turn the lights on if I absolutely have to, keep the water lukewarm and haven't yet turned the heating on.

I spent 18 months with the furniture parked in front of the radiators, cooking as quickly as I possibly could to use the least amount of gas and electricity. I unscrewed the lightbulbs in the hallway, unplugged everything at the wall so not even the LCD display was blinking away on the oven. I eventually turned the fridge and freezer off – they were empty anyway – and the boiler, desperate to save money, shocking myself awake in the morning with the shortest, coldest showers, and boiling a kettle of water twice a week to bath my young son.

But still, there are some corners that can't be cut. The clothes still need washing, especially when potty training a toddler. You debate every cup of tea, wonder how much it will really cost, and put another jumper on to try to keep warm. You go to bed when it gets dark in the evenings, because it's warm in bed and you can't see anything anyway.

You go to a coffee shop where the staff are friendly, early in the morning when they're unlikely to be busy, and plug your mobile phone and the small notebook computer you borrowed from a friend into the wall to charge it. Anything to save a little money, anywhere you can.

I'm not the only one. I visited a single parents' support group in Bristol a few weeks back as part of an Oxfam project, and the mothers I met there all told the same story. How gas and electricity bills were one of their biggest outgoings. How they don't quite understand how it can cost so much, when they don't put the heating on, or luxuriate in hot baths every evening. An £18 standing charge to be connected to the mains might not sound a lot to some people, but to others, spending almost a fiver a week without so much as turning a tap on is the difference between eating and missing meals.

We hear time and again what a prosperous, affluent country Britain is, the sixth richest in the world. But aren't we ashamed that people who need emergency food handouts are eating cold beans and stewed steak from the tin, or handing it back, because they can't even heat it up? The Trussell trust and some Tory peers have called for an inquiry into poverty levels in the UK today, and it can't come quickly enough.