Can't correct/amend e-mail address for account

Please advise how can I find a capable person at Telkom, which could just change the e-mail address on the Telkom account. 1. I phoned in, got se most rude consultant, still not fixed. 2. Had to go to my elderly mother, at her home, had to assist her to phone in herself, they promised to change it, still not fixed. 3. Now what do you suggest we do, if they can't correct the e-mail address, how can we be expected to pay the bill?