Passing on the buck while I have no service

I purchased an LG G4(***) in July 2015 and in December 2015 the phone started to malfunction and heating up when I charge it. I took it back to the mtn store Somerset west mall and the so called LG Expert in the store said it was a software upgrade required only. so he purported to have upgraded the phone and it on lasted 5 days and i went back again and he said had fixed it again. after 2 weeks I went back again as it was getting worse and requested a warranty assessment but he turned me down saying it was minor and he had fixed it. The 4th time i went in on the 13th of February 2016 with the same problems and sited once again software and then I pressed on to have a warranty assessment only to be told that the warranty period was now over by a few days so I then asked for it to booked for repairs. on follow up i am being told its awaiting spares its almost a month now. Am I ever going to get a replacement phone? why wait this long without a phone while I am paying. sme1 *****ed me of my warranty assessment saying it was software now a few days later because my warranty is past they say they are awaiting spares what does this mean? I need value of what I am paying for.