I won't pay for Vodacom to pay me back later

I have been with Vodacom for as long as I can remember but never before have I had this. I went to upgrade my phone and suddenly I'm charged for a migration? Now I pose the question I'm upgrading and offering to pay you more money for another 24 months why would I pay you a once off fee of 1397-07? I would need to be stupid, someone messed this up? Now because I refuse to pay this amount you lock my line? Really you suggest I pay the money and then you can raise the query and maybe get me a refund. Well to hell with Vodacom I won't pay you another cent of my hard earned money I will hit where it hurts. 4 contracts will now move to someone who is prepared to resolve my issue not just eat my money