MIGRATION FEE DISPUTE - beware!!!

I have called Telkom 4 x in April to resolve this matter. *** .. a superior will call me back.. so they say. I upgraded /migrated my current contract from 10gb to 20gb, to a higher plan. This you can only do in store. The person that helped me did not tell me there is a migration charge of R950, nor did I sign anything. This amount has already gone off my debit order and I want a credit. In the first place I did not downgrade, you have no right to charge me that. And to not say anything.