Frustrated, customer service sending me from pillar to post!!!

If there was an option to give zero stars, trust me I would. I was offered a settlement discount after which I was informed that I could terminate my account after paying. I paid the amount and sent a POP immediately after which I asked for my contract to be terminated. I am still getting calls and they have not stopped billing. I get daily harassment texts and calls telling me I'm owing again after stating I need my account terminated as I no longer have the vehicle in question.