Refuses to do full refund on double paid account

A double payment was made i tried to rectify it by contacting Vodacom's account department they told me to fax proof of payment which i did phoned back to confirm that they had received the proof of payment. All good i was asked if i want full refund or only partial i explained full refund. They noted that it would take 7-10 working days to check if it is a legal claim. <br> <br> However when phoned on the afternoon of day 10 i was told that they could not do a full refund on the amount etc. I'm having on going problems with vodacom and after just renewing 1 of my 2 contracts im considering to cancel both my contracts with them and look for a new service provider.