False advertsing/ fail to honour warrantee

I have a contract with Vodacom, I have the sony xperia Z1, I was experiencing problems with the phone, I then took the phone to Vodacom to sort the problem out, I first went to Westgate mall and the guy there said that it was a common problem and said I must take it to the closest Vodacom shop to me, I then took it to the Vodacom shop at the Cresta Mall, the person there said that they could not fix the phone it needs to be replaced, the phone is still on contract and it is less than a year old, I went myself to Vodacom world in Midrand, I booked the phone in and they said repairs take 7 to 14 days to repair, after 7 days I called in and they said it was ready for collection, when I fetched the phone, they said it could not be repaired and if I want a new phone I need to pay for it, I told the lady the phone is still under warranty and it is still on contract, I phone was advertised as a waterproof phone, Vodacom need to sort out this problem I've been fighting with them since February and have received no help, but they expect me to be paying for this contract with no phone, I need this to be sorted out asap, I'm tired of this **** service, and the phone is still with them.