Useless customer service

I signed up for a data contract online and was never sent the contract details. Once it elapsed I was billed out of bundle rates without ever being notified by email/sms/call. I then signed up for a new contract and am now being billed extra 'early upgrade fees' for a contract which has already lapsed. How on earth is that possible? I've been into 2 stores who say they can't help because the contract was taken out telephonically and the departments are different. There's no care for the customer and people are mislead into signing up with false information. I was told to wait for my monthly statement as they couldn't even give me a breakdown of my fees from their system.