Telkom changed my number and refuses to see why

Today I experienced service I didn't expect from telkom and one of their so called professional consultants Ayanda. My contract was taken out with telkom 2 years ago with a number I had from cell c ported to telkom. All of a sudden my number changes from that to a new number. I never requested this change and yet telkom customer service centre knows how to answer calls, they know little about getting down to how they can solve the issue. They have no knowledge of my old number. Ayanda that I spoke to today tells me I should speak to cell c about my issue. I don't know how they would be able to assist. Up till now I sit with my head down disappointed at how it was simple for them to change my number yet so difficult to find out why or how or whats the process to get me my number back. I have been trying to hard to get this sorted so I could proceed with my upgrade. I guess it's bye bye telkom