Never assist with payments

Every month Telkom mobile deducts, my account but the amount deducted is never the amount my unlimted contract is for (R1599) ,always LESS ( -R990).My salary gets paid in the same day or sometimes after the debit order date so the debit order gets reversed. 1st time I missed payment I went to the telkom mobile store (East Rand and Alberton) to go pay my account, telling me the facility is not available, Alberton 8ta told me to pay at Checkers they couldn't assist me. Contacted customer service (180) before I got the correct banking details after payment was made proof was faxed. 2 days later I was reconnected. 3 months of incorrect amount deducted, my salary only got paid after date of deduction. I got someone to do payment from there online bank acc i requested to be reconnected. Telkom informed me I have to pay an extra R2400 after paying R1599 because my account is behind (debit order amounts) before they will reconnect me unable to use my online banking. I enquired if it is possible to pay online with my credit card, they rep**** no online facility, but you can buy airtime or data with your credit card online. I know I am also at fault but the payment services are very poor!