Mtn
Took phone to be repaired 4 times in a row!

To whom it may concern,
I am very upset with the service that mtn is providing. I took my phone in to be repaired at the beginning of June. I went in a month later (they did not even contact me to say that my phone was back in the shop), I put the phone on in the shop and the problem was still the same. Sent it in the second time, about 3 weeks later I went to fetch it again, thE first problem was fixed but then the 'k' key did not work! Today, just short of a month later, I went to pick it up and the 'k' key still does not work! It has now been sent in for the fourth time! This is getting completely out of hand, we pay a high fee every month for this phone and its features yet are now stuck without it. Please advise me on what step to take next? Thank you very much!