PLEASE GIVE ME MY MONEY BACK

I paid Vodacom an amount that was due to them but turns out they also debited my account and the amount i paid was covered in the amount debited, i called in to get a refund and they said i must send a proof of payment which i did, the pop was emailed and faxed through to Vodacom but they keep saying they have not received it. The guy I spoke to today says that he can see the fax but not the attachment, how ridiculous! I faxed the proof of payment VODACOM and i don't appreciate you wasting my time like this! Please process my refund ASAP!!!