Faulty Phone, Booked in 4 times, No fault found

June 2015 I upgraded and requested the new Cat B15Q handset. After a week my phone is suddenly off. I was able to switch it back on thinking it may have been the battery only to realise that the battery was still full. As days passed, it occurred more often that the phone just switched itself off without having a low battery. I decided to take it in to Vodacom repairs. First job number ***9. Received phone back stating a software upgrade was done. The phone did not even last one day then the same happened with the phone just switching off. Took it back to Vodacom repairs, Second job number ***6. The technicians couldn't find fault with the phone and returned it to Vodacom Cresta for me to collect. I was still busy changing the date settings after I collected the phone and it happened again. Back to Vodacom repairs, third job number ***4 and still no fault found. The handset is faulty and continuously switches off. Took it back for repairs the 4th time, requesting that the manufacturer's investigate because there is definitely a problem. Received sms, they cannot find fault and I can collect the phone. I am paying for a faulty handset. This phone needs to be replaced.