contract expired

I had called in on the 7th of April to find out when my contract is expiring and found out that it had been expired already and the then the agent George advised that he cannot cancel the contract, the retention team will contact me in this regard and will back date to the date that I had called. I gave him the number to contact me and up to this day, I have heard nothing from anyone. I want this contract cancelled immediately and no debit to come out of my account at the end of the month. George advised that the retention team will contact me with 3-5 working days. I have been trying all the numbers listed on the web and none of the number allow me through to the customer service department. I listened to the IVR and waste my time and airtime. This is very poor service. I need a response asap.