Very very poor service

I have upgraded my account in March and was advised that I'll be paying 199 per month after a month or 2 I started getting calls that my account is in arrears and that my contract amount is actually 500+ which I have not signed up for. I have been trying to get this issue resolved but I'm being sent from pillar to post. I had a service request logged and never received any feedback. Now I'm being harassed by debt collectors after I have been trying to get this issue resolved. I have also requested that the recording of the upgrade conversation be sent to me and then I was told that I have to speak to a specific department and when I was put through to that department they could not assist me. I am now at a point that I want nothing to do with this service provider coz they are not providing me with any service. I am more than willing to pay for my 199 from date of inception but nothing else.