ADSL Line Upgrade not completed, no services since the 17th of Nov yet invoice updated

I've requested an upgrade of my existing 10Mbps ADSL line to 20Mbps. (order number ********** -31) A Telkom engineer phoned me on the 16th of Nov, informing me that he will be doing the upgrade, and that he would phone me back once he completed the work. I did not hear anything further and during the evening of the 16th I did a speed test to see if the upgrade was successful. test results indicated that the line was no longer 10Mbps, but instead of upgraded to 20Mbps it was downgraded to 2Mbps. Because the techy did not phone me back to confirm that the upgrade was completed, I left it there. Returning from work on the 17th of November, the internet was no longer working and after attempting to reconfigure the router I found that the line was down. I logged a call the next morning - 230CTK181117. Since then I have been battling to get proper feedback from Telkom, and phoning 10210 is a complete nightmare. Most of the times the feedback is that the fault was not assigned to an engineer. On the occasion that it was assigned to an engineer the feedback was that they would request the engineer to attend to the fault. I managed to get the details of the tech who did the upgrade but was told that he cannot help me because the line has to be fixed before he can try to upgrade it again. He also could not assist to have someone attend to the fault and only said that I should phone him back once the line was fixed. I tried requesting a downgrade but was told that I have a 24 month contract and have to pay penalties. According to Telkom records the upgrade was successful and I am liable to pay for 20Mbps instead of 10Mbps. On Saturday I received a phone call from a tech from Telkom, saying he was at my house and wanted access to attend to the fault. I was not at home and knew I would not be able to get there within an hour. I asked him to return at 15:00, he agreed, and I never heard from him again. I really really really don't know what to do any more and I cannot listen to the same irritating tune for another 25 minutes just to be told that the fault is not assigned to a tech and that it will be escalated to a supervisor just to hear nothing ....