Dear Guest, Spark has taken on more staff and upgraded the billing/CRM system they are using so if still having issues, please get in touch. There's now more ways to do that. As well as the phone number 0845 034 7474 you can also get Spark on Twitter and Facebook at http://www.twitter.com/sparkEnergyUK and http://www.facebook.com/SparkEnergyUK.

From those sites Spark can give you a direct email address for getting in touch with someone if you are still having issues.

Spark are also encouraging as many people as possible to switch over to Smart Meters for more accurate and up to date bills, as well as more flexible payment methods.

You can find more details about all the changes at http://bit.ly/spark-changes

I sent them four, these were all ignored. They have apologised for the mistake but said that I still owed them the money.

What I queried is where did those units go? when looking closer at my bills, the "previous meter reading estimate" (on the new bill) was not the same as quoted in the last months bill, which is legally according to CAB and CD should always be stated on your bill and the estimates should flow one-to-the-other. Therefore between each month there was a discrepancy of approx 50-100 units of energy each month. Not really noticeable at first but when you get the whole collection of bills and view them side by side you realise throughout the year Spark has not charged you for the units you have been using. Hence, by the end of the year the discrepancy between the first meter reading and the last will leave you with a huge bill. This according to Consumer Direct "the method in which spark produce and estimate bills is unclear and therefore unfair to the consumer".

Thanks for the advice about the bank, I was naive to think that the bank would give me sound advice, next time if anything like this come up I will do this. At least I have learned something valuable from this experience, every single bill I get through from a company will be double checked against the previous one.

If you monitor your own energy use by reading the meter regularly you should be able to avoid unexpected charges when you leave especially now they have to write to tell you when the unit prices go up and you have the right to move before the increase becomes effective.

Next time you have a direct debit taken twice (or by mistake) simply ring your bank up and tell them you want a refund under the direct debit indemnity guarantee and they are obliged to simply refund you without checking any of the details. Don't be fobbed off with the bank saying you have to speak to the originator - they have to do it without asking questions and it's then up to them to get the cash from the originator

I have had enough! customer service from day one was horrendous, but I couldn't switch without permission from the landlord. I was charged 30-40 a month and now that I have left they sent me a bill for 170!! Where did that figure come from!?!

They play down how much energy you have used so you stay with them, until you move and you are stung with the full whack. I worked full time and lived on my own, no dishwasher or any high energy appliances, in addition all my water and heating is gas. I find it hard to believe that I have used over 500 a year on lights and laptop. I dread to think of the amounts they are charging for a family of four etc.

There's all sorts of other things that came into play, they once overcharged me for a month (over triple) which led me to become overdrawn, it was their mistake but they refused to give me my money back and told me that the only thing they could do was credit the money against my account. There was no apology and no compensation for the overdraft costs.

In addition, to incorrect amounts and even incorrect accounts they seem to be one of the worst energy companies around. Even if the big 6 are a bit more expensive at least they seem to be up front about it and don't sneak charges on at the end.