Lying, cheating, *****ing....

I have an LG G4 on contract. Phone just died after using for a year - was told by MTN that all G4's does that after a year. Took phone to store to repair as i am still in my contract and that is a manufacture fault. Got quoted R2700 to repair at first, queried as i didn't break it and i am still in contract - Repair centre didn't get the proof of purchase. Then i was told it cannot be fixed so they will exhange my handset - was told that on numerous occasions. Once again followed up on a daily basis to confirm when i can fetch it - paying for a contract but have no phone... Last week Thursday when i followed up again was told my phone is at store, I can go fetch it. The phone they handed me was in a terrible state and i didn't accept it. Was then notified that they exhange with a refurbished phone, which is fine but then it needs to be the same look as my phone. Manager agreed that phone should not be in such a state and she will escalate. Called every single day for feedback. Now today, i get told the motherboard is the only thing that was exchanged and it is my phone that was sent back???? after i was told on numerous occasions that my handset has been exchanged, NOTHING ABOUT A MOTHERBOARD. In actual fact i was told that it could not be repaired - now after fighting every day they want to tell me that the **** they wanted to hand me was mine that i handed in at the store??? How did my cover colour suddenly change as well. The manager wants to now give me attitude because they cant check every phone's cosmetic colours when people hand it in for repairs. I feel cheated, **** and ****** from. I will not accept that i pay for a contract where the phone has a manufacture problem and they now want to give me a phone that looks like ****!