Pathetic service from Hisense South Africa

Been struggling for months now with Hisense, the tv has a problem where it keeps changing the date and time and locks you out of everything, been going back and forth with Hisense SA and arrangements was made to send a tech out to me which i have been waiting for now for morecthan a month, then suddenly i recieve a sms and email stating the call has been closed, but yet no one has attended andvtoday the problem is back again, once again i had to factory reset my tv, this is an ongoing problem, please help mevgetvthis issue resolved