Telkom is crippling my Business - Utterly Appalling

We run a Dental practice and neither myself nor my staff requested our main landline number to be diverted to a mobile number, but nevertheless it was enabled. The said mobile number belongs to an ex employee, also, none of my current staff knows that mobile number since they started after she was gone and there. Thus either the said ex employee did so or it was a mistake by Telkom. I contacted all the usual telkom numbers, none of the Telkom staff can tell me when, how, who enabled the divert. This of course started Monday, however since especially mobile users calling the landline number cannot get through to confirm or make appointments it is causing harm to my business, financial loss and damage to our reputation. I looked but find no place one can lodge a complain, internally. Also the fault have been logged this morning yet nothing has been done at the time of writing this. I have brought this under one of Telkom's Group Executive's already since this is not something that is suppose to happen and even then, responsible protocol should at the very least take note of when and how the divert was enabled. Giving me a response "I dont know who or when" is not an response at all. Also how is it even possible to speak to management if there is no oversight department or if so what is the email or contact details? Well like I said, I already brought it under attention of one of Telkom's most senior Staff and if this not resolved with proper recourse than I will not hesitate to escalate this to Telecom Regulators [ICASA et al], and if that dont work then I will take this matter to the Department of Communication. I expect responsible and proper conduct, not excuses, staff contradicting each other, and I will ensure that this is dealt with in a way that is proper, responsible. Essentially this created a causal effect and I am sure I am not the first who reported this. This was reported on all of the forums yesterday without any resolve. Today, when I called none of the people "exist", there is no "record", and or the Telkom staff are not whom they claim to be.