complaint

Hi I purchased a tab from your company last year which I am still paying R 382 for until today.the phone worked for 3 month and had a charging problem.I don't know who to contact or where to take it to get it fixed because the last time i spoke to someone was when your staff was still selling me the phone and i have never recieved another call from your company.I don't know whether its your culture when it comes to treating your customers service.i would like a response soon because now I am paying for something that is off no use to me.