Worse service and not keeping to contract

In middle January i went to Telkom in festival mall kempton park. I got the double your data deal which was 5GIG = 10GIG @ R249 p.m. When my sim was activated i saw that not all my data was there . On the 1st when my monthly data came on it was only 5GIG and not 10 as agreed upon. I phoned on the 1st and the said they see on the system its double data deal and someone will phone. Up until today after numerous calls it is still not sorted out yet i received a statement with full payment that wil go off by debit order. So i am supposed to pay for something that Telkom should give but obviously cant. I have phoned every day and they wont even put me through to a manager. The message centre via facebook is useless and keep asking the same questions without doing something. Call centre keeps saying they will come back to me but they dont. Worse service provider i have encountered!!!!