Vodacom charging twice for the same service!

I moved my number from my father's account to my own 7 January 2021. I signed a form stating I will be billed R130 for the switch and I was happy with that. For January my father was billed the my full account. Now end of February I was billed my full account and the pro-rata portion of January so thus Vodacom billed me twice without informing me of the additional costs. Otherwise I would have moved the end of the month?? I need to be re-funded that as it was just an account swop and there is no need to bill me twice. That is just *****ing. I demand a refund or I am moving my business to a more transparent company. The call center was also no assistance.