Service delivery

I am extremely disappointed and furious at the service I've received from Samsung South Africa (Constantia park, Roodepoort). I booked my phone in for repairs on the 1st of August 2017, after paying for the repairs & sending them the proof of payment, I still haven't received my phone to this date, no one gets back to me regarding the status of my phone, I am the one that is calling them all the time. They keep on telling me "By the end of the week" for 4 months. This is totally unprofessional and unacceptable.

This is my last resort, I have absolutely no idea what else to do to get my phone.