Hisense, nice phone but BAD SERVICE

I have a Hisense Infinity H30 cellphone on contract at MTN. This is my 2nd Hisense phone and I quite like the phone, but this will surely be my last Hisense phone. I gave them 2 stars just because the phone is nice, but for after sale service they get just 1 star. About 3 months ago the screen started becoming unresponsive a few times a day. It got worse and worse and at the moment the screen is so unresponsive that I can hardly use the phone. My MTN consultant referred me to the Hisense depot/service in Milnerton, with a proof of my contract. I went there on 24 Aug and the guy in the depot told me that he has to order the screen from JHB and it will be there on Thursday 27 Aug or Friday 28 Aug at the latest, and he will call me to bring my phone. Replacing it takes just 20 min. He never called me. When I called him, he said it will be there Wednesday 2 Sept. He still did not call me. I tried to call the depot numerous times (±30 times up till now) but they never answer the phone. When I complained (twice), on their Facebook page about the bad service, a rep phoned me on 10 Sept and said that he will sort it all out. He promised me that the screen will be in CT on Tuesday 15 Sept and he will call me. To date nothing has happened, nobody called me. The Milnerton depot still do not answer their phone and the rep has disappeared into thin air. When I phone him I get no response and can not even leave a message. BAD SERVICE HISENSE, BAD SERVICE !!!