Thanks - look forward to advice Breaking Point

I ordered goods from Kaleidoscope by phone and paid at the time by credit card. During a claim for a part-delivery missing, an account was opened for me without my knowledege. I have since reveived the missing goods, however I have been receiving invoices for same goods already paid by card. I have phoned and written many times to customer services and debt collection depts. sending copies to both. They do not read my letters explaining that I don't owe them money and I do not want an account but keep saying "sorry about the missing item..." etc. What can I do now to end this nonsense the quickest way possible and with least pain to me? Thanks

Transport for London have sent me a PCN saying that they wrote to me in October and I did not reply. There is NO WAY that they sent me the first notice. I can't prove that they didn't send it and there appears to be no burden of proof on them that they did sent it (and that it was delivered). So I now have a letter increasing the fine and no right of appeal. I firmly believe that this is a strategy they have adopted to intimidate people into paying up huge sums of money without putting TfL to the bother of dealing with an appeal. The PCN itself accuses me of parking on a red line but there is no time stated on the notice and the place they say I parked is a bay with permission to park at certain times,so I definitely WANT to appeal. What can I do now? Thanks.