After appalling service we tried to leave nPower but after almost 9 months nPower have still not closed our account!!! During our time with them they cancelled our direct debit then billed us for £53. Five months later they cancelled it again and demanded £401. We moved to a new tariff, 6 months later we were back on the old tariff! August, we sent final readings and left them, they acknowledged this. October they apologised that we were still on the wrong tariff! December after long phone call they said we were in credit £122 but would close the account and refund us. A few days later they told us we owed them £193. We had a 1 ½ hour phone call in March said they would sort it. May they said they will close the account in 50 days! After many emails, phone calls and letters still nothing, a total nightmare.