Outgoing call centre sent the wrong phone

Good day. Towards the end of August Glasson contacted me to upgrade my phone beginning of September. We discussed the iPhone 6 Plus and 7 plus. She assured me she would find me an iPhone 6plus 64gig. The phone was supposed to be delivered 5 September. I tried to contact glasson but she wasn’t answering her phone or emails. Eventually she came back from sick leave and it was explained to me that the couriers have had the wrong number all along. So it was eventually delivered (late) on 13 September. It turns out she had the 16gig sent to me!! As per the lady at the cal centre I returned the phone to a mtn store immediately and requested that the upgrade be cancelled. To date this has not happened. I’ve lost out on an icare package from the istore which included an extended warranty. I’ve visited the mtn store where I dropped of the phone twice now and still no joy. Your service department on twitter said that it has been escalated but nothing seems to be happening. Today your agent Phoned to enquirer about upgrading my other phone and when I asked about the relevant upgrade he told me it had been cancelled and I could visit a store for the upgrade. However when I was at the store the upgrade still wasn’t canceled. I’ve been with Mtn since the very beginning and the fact that no one is taking responsibility or actually doing anything to help is unacceptable. Please also put me in contact with Glassons supervisor. I can see from this website I’m not the only unhappy person.