Telkom - Service and advise

I had obtained a 24 month mobile contract with Telkom mobile.<br> Terms of which were as follows:<br> I paid R400 a month and was on a smart plan 150 and received additional 5 gigs a month as a promotional offer during this period of signing up.<br> Before my 24month contract came to an end I contacted Telkom to enquire what will by invoice amount be going forward once the 24 month contract had been concluded. <br> The call center operator told me that I will be only charged for the service which would be R150 a month. <br> My contract ended in November 15. When I received my invoice for Nov15 the invoice amount was R150 which was correct as per the call center agent. <br> In December 15 I received my invoice and now the amount is R816.<br> I have called Telkom but have not received any assistance from there operators to solve my problem except for providing me with a case number (***6)<br> I had called the call centre on receipt of this bill as well as subsequently and now for a 3rd time with no help.<br> My issue is that I was mislead and second I was told the 5gigs were a promotional item, so why did it not fall away like other promotional items do.<br> <br> <br> <br>