Extremely poor workman quality

I sent in my phone for screen damages at Samsung Eastgate shopping centre. I paid an amount of R3800 to repair the back and front screen of my A5. I took ownership of the damages as I was negligent. When my phone was in for repairs I was never contacted on the progress of the phone I had to call every three days becaue I was promised it will be fixed the third day, which it wasn't. When I eventually received the phone, I immediately got a cover and screen protector to protect my phone. 2 weeks down the line my phone started showing a purplish blue like substance on the screen, it got worse in about 2 days. I then took it back to Samsung Eastgate, and I was told it was physical damage but there where no signs of such on the phone. The technician didn't want to accept that it was poor workman ship or quality of the screen. I was promised that it will be fixed and I'll be updated on the progress. It's a week now and I'm still waiting. I have no smart phone as we speak. This is a an inconvenience as I use the phone for business. Maybe another brand will do as I've seen repaired screens have been fixed properly the first time. I'm extremely tired of going to the ship because I know I'll be disappointed.