It took them months to finally send me a bill but that was not correct, over the next couple of months I received nearly 15 different bills and threatening letters. I then managed to speak to someone who apparently gave me the correct amount to pay, once paid I was told the acccount was closed. A month later more and more bills started to come again. In all I received well over 20 bills, 10 different amounts to pay and also affected my credit rating. I have sent this to the energy ombudsman to help try and sort out. Resolution was disappointing, £75 rebate and a letter of apology.