I’ve never believed you should trust your day-to-day financial affairs to anyone but yourself.

However financially illiterate you are, you’re still usually better placed than anyone else to make sure you’re getting the best deal possible.

That’s because you have your own interests at heart in a way that others don’t. Take “expert” advice by all means but always examine it with a questioning eye. And, as my own experience has shown in the last week, never ever trust a utility company when it comes to direct debits.

Regular readers may recall I’ve recently changed phone and broadband provider and am now paying £25 a month less than I was. But when I checked my final bill with the old company this week, I was surprised to see a month’s advance direct debit payment was about to be taken, even though I would be using its phone services for only two days of that month.

I queried the charge and was told, by someone in a call centre on an entirely different continent, the charge would be refunded the following month. My attempts to argue that the money shouldn’t be taken in the first place made no difference. So I did all I could do in the circumstances; I cancelled the direct debit, meaning they had to send me a bill for what I actually owed. It’s a good job I did, as the outstanding amount was £40 less than what they had planned to take!

In the meantime, my £100 high street shopping vouchers that were also part of the phone-switching deal have arrived. Now, should I blow the money on something I don’t really need or save it for a rainy day? I think we all know the answer to that one...

• Inspired by thrifty reader Jean Clarkson, who wrote to me about her user-friendly, ethical phone and electricity providers, I’ve started recycling used envelopes.

Jean’s thrifty credentials were obvious to see before I’d even read a word of her letter, which came in a recycled pre-addressed envelope. Following her excellent example I delved into my recycling bin to salvage and re-use all the old and unwanted envelopes I had so carelessly tossed away. Thanks Jean!

• Email Sheena or tweet using #ThriftyLiving.