N Power have been overcharging me for my energy consumption as long as I have been with them, I asked them to fit a smart meter so I could monitor my usage and they responded with 'by law we have to fit all customers with one by 2020, therefore you will receive one by then'.... in other words no! Therefore I decided to move supplier, this is when the trouble started! they sent me a final bill of around £350, this was based on 'estimated' meter readings therefore I entered the 'actual' meter readings (which were lower) on to my online account, the amount owed then went up to around £420! I called them to query this and they insisted this was correct and I must pay this amount immediately or they would stop my switch, I received numerous emails each day telling me to pay the outstanding balance, I didn't pay this amount therefore they stopped my switch! after numerous complaints we came to the conclusion I owe them £50 so I paid this and the switch continued. The following month I received another final bill in which I owed them £181! I queried this and they insisted it was correct as it was generated from my 'actual' meter readings, after weeks of emails and phone calls and threats of taking the complaint further with an outside organisation today they have informed me that the actual final bill is £6 and the readings were 'estimated' hence the huge over charge. If I had of paid all these amounts when they were demanding forcefully I would be hugely out of pocket now and in debt, there is no explanation what so from N Power other than 'as a gesture of good will' they are adding £6 to my account to write off the final bill. I have been with my new supplier around 14 days and have already had a smart meter fitted...............