New I-Phone 6 sent 3 times for repairs in 3 months

Initially the phone had a speaker fault, Vodacom Repairs Durban sent it to Johannesburg for repairs, the feedback was nothing was found to be wrong with the phone and it worked. In less than a week, the same speaker fault came back. Vodacom Repairs Durban booked it in for repairs but sent to Johannesburg about 4 days later, after that I was given a ''replacement'' phone. This replacement phone now just freezes on start-up, tried to reset it as advised by Vodacom but no changes. The phone was bought in July 2017 and the job nos. are ********** 3, ********** 2. When I asked who do I need to speak to regarding getting a new phone, the lady told me to call ********** Claims department, but Claims Department said they cannot make the call to replace only the repair centre can decide. This phone is on contract and I pay every month for such a pathetic service.