Settlement

Last month (September),I requested a settlement amount for my contract. The settlement amount was sent, with the banking details etc. I paid in full, I sent my PoP to cancellations department as requested on the form and never heard back from them. Three weeks later I emailed again to ask if things are in order and still no response. I called customer care, they said I need to pay for October then everything will be settled. Today I called again, and now apparently they don’t pick up the amount that was paid in, but they can tell me exactly how much I paid in after verifying my details. Somewhere someone didn’t do their job properly now I have to continue to pay a contract which I have settled and no one can assist me and no one responds to emails. What is going on!