Defect iPhone

I bought an iPhone 6 16Gfrom Vodacom via a contract on the 24/10/2014. The phone had a speaker problem on the 21/01/2015. It was then exchanged with a brand new similar model.<br> <br> I then got another iPhone 6 128 gig. Then phine started giving smae speaker problem. It then got exchnaged a couple of times.<br> These are the job numbes.<br> <br> 1. ***3<br> 2. ***0<br> 3. ***6<br> 4. ***1<br> <br> I keep wasting my time with th defect iPhone i receive from Vodackm and Vodacare. I'm not happy with the phoke model Vodacom has given me. And i need a resolution to this as Im tired of wasting time at vodacare. My petrol money and business time is being wasted by Vodacom.