Migration from 10GB to 50GB

Every time I go to the Sandton store there's an excuse or 1 outcome. Back Office will call you or I do not have the correct documents. Back office NEVER calls. When I phone to add GB's it happens instantly. When I want to migrate from a 10GB to a 50GB, they just find an excuse. PLEASE HELP ME!!! This is like the 5th time I have been to the store in Sandton and like the 5th complaint as well. Still nothing done. When I want to cancel, they say I cannot without paying the full account off. What *******. If this is not sorted out before the 1st of October. I will put a stop order. I encourage everyone not to purchase from TELKOM ever. Rather do Cell C, Vodacom or MTN please. They will threaten you.