No response on ongoing matter

I have sent a dud Sony phone in through Vodacom on 30 January already! I was notified that the phone was ready for collection but not repaired because of liquid damage... Uhm yeah... that is why it was sent in in the first place, a waterproof phone that had water damage with no fault on my part. Used it as instructed!! So having no luck I wrote report on Hellopeter and got very quick response from Jason Welff from Vodacom asking for some information. That was 2 March. I have sent two more mails after that with still no response from him or anyone else! What kind of customer service is that. I am beyond frustrated with Vodacom and Sony at this stage! They are quick to sell you expensive phones but when it is an obvious dud you are left hanging! I bought the phone through Vodacom so I would expect some help from them getting it sorted. At this stage Cell C has been more helpful in trying to sort it out with Sony, and my contract is not even with them!