Refusal to an obf for a very high end device

Took a phone on contract on 29th Jan on the same day I noticed the phone overheating so I called the store , the lady told me the rep would contact me to reassure me that's it's normal and would subside. 4 days later it continued and got worse so I took the device in to be sent for assessment as an obf. It's been a week since I sent the device in and have not yet received it when I called the repair centre I was told the handset was booked as a repair and not for assessment as an obf and if it was booked in for an exchange unit that is exactly what i would have gotten and when I went to the store I was told by the store manager xolani that the area manager instructed him to do the booking that way. I'm so upset with telkom because they did not follow protocol and I refuse to take the handset back after it being repaired it's a very expensive phone and the chances of the sane thing happening later on is very high. The area manager refuses to take accountability for his actions and says that should we have the same problem we still have a valid warranty . I asked for a written reason as to why the handset cannot be replaced the area manager refuses , I asked for a contact number for higher Authority I was denied that also so the way I see it is telkom hires people to do as they please and not follow protocol , I am well within my rights to get a new phone as the phone was returned within 7 days. The store manager also told me the area manager asked him to 'beg' us to take back the phone I have all this on a recording I need someone to take responsibility for this as I am not taking this handset back i demand a new phone .