Vodacom Repairs Lakeside Mall

In January 2018 I upgraded my Vodacom contracts and took out an additional contract for a tablet. The on LG K10 phone has given us nothing but problems. It was sent in for the first time in June 2018. There were no problems with the screen as it had a screen protector on. It came back with a crack and we thought it was just the screen protector. The devise was still doing the same and when we tried to send it back we had problems as they said the screen was cracked. The phone had been in more than 6 times. Was sent to head office for assessment and each time they just replace the motherboard. It come back and a week or two later we have the same issue. There is something that is causing the mother board to blow as the other 3 LG K10 phones that we have do not have the same issues. The mother board has been exchanges at least 3 or 4 times. I have called client services and asked to speak to someone at the head office and am told that they are not able to transfer us and when asked to speak to a manage they are never available. I have spoken to Johan Kruger at the Lakeside repair centre where the phone has been sent and he dies not have a solution for me except to bring it in yet again. All the petrol that we have used to keep taking the phone in could have already paid to replace the device as it is a 90 km round trip every time we need to take it in. I am really not happy with the service that I am receiving in this regard. Please advise as to how we can solve this problem as I am paying every month for a devise that cannot be used.