Closing my account - been given run around

I have been trying to get my account to be closed after settling it. I am being given a run around with no confirmation despite the fact that I have mentioned I can't afford it anymore, hence I opted to settle the account! I am being tossed from one call center agent to another throughout the month until next payment date. Now I'm liable for the payment of interest which is not my fault as their turn around time is shocking.