Pathetic Customer Service

My contract ended in April, I was told I need to call to cancel the contract as they will be loading data and minutes and I will be charged for that, not knowing why is it so hard to cancel a contract at the store whereas I opened the contract at the store. I have been calling with no one to respond, forever on hold with no assistance until May after they loaded data and minutes. Now I have to pay when I don't even have money to do that or else I will be in debt. How pathetic, I took that contract at the store, not over the phone!!! I am never using telkom again