Useless Handset given for Upgrade

I upgraded in November 2014, I was given a Sony Xperia M2 Aqua, believing it was a good phone...as per all the adverti*****ts...but in the last 2 months, it has had to go back for repairs 3 times! The only comment I got from Sony was that it will be repaired under warranty and no payment from myself...that doesn't help the problem of not having a phone!!!!<br> It looks like every month from now on until my next upgrade in 2016 I will be without a phone for 2 weeks at a time, or have to bother people to borrow a handset until I can get my one back, that will probably have to go back again and again.... If a handset gives so much trouble within the first year, is there no way of changing?? It's an inconvenience having to keep going to Vodacom Repairs to have it fixed!!<br> <br>