4th time my Samsung S4 is in for the same issue

I have a Samsung S4 handset, the phone has been booked into the service centre for 4 times now. The first time around the phone overheated and the battery was swollen. The phone battery was changed and not sure what else and I lost ALL my data, The second time the phone was overheating and the battery was not even lasting a full day - this was fixed and had to take in the phone for the 3rd time, this time around I was promised by Wim, the manager at the branch that the phone has been fixed, this was not the case. The phone is now in. It has been over a week and I just received an invoice from the service centre for R500 to fix the handset. Wim the manager told me that they only fix a phone 3 times and they replace it after that. They never get back to you. Nobody ever answers the phone, it just rings with no option to leave a voicemail. The service is appauling, you get random calls to rate their service and nothing is done about it. The staff tell you things like 'if you pressurize head office they will upgrade your phone'. I will NEVER EVER use another Samsung product. I have a laptop, fridge, tv with Samsung, never again!!!!! They don't even offer you a spare phone to use.