Payment of arrears on a suspended service

Telkom installed an WiFi in early (February) 2015 but the set was incomplete despite repeated requests we never received the ****le. Payment using internet banking was then problematic and could not figure out what the problem was. I called Telkom but could not be assisted.I went to Hatfield in March and was advised to pay at pick 'n pay and thereafter I can be able to use internet banking. I tried internet banking after the visit I still failed and I called Telkom but still no assistance. Due to the nature of my job, I don't have time to go and pay at PnP. .The WiFi service was then suspended in April /May 2015. I waited for the invoice nothing came. Then I app**** for a property finance then the bank asked to send proof of payment forTelkom account. I went to Hatfield to enquire abouts the account. I was told that I owe R3920.50. This include all the months during which the service was suspended. It means I have to pay for a service that I never received. Telkom says it is bcos of the contract. How can I pay for something that I never utilised? My credit profile is now negatively affected. Today I paid R1500 at PnP bcos I'm scared I will be blacklisted. Please assist.