No phone after 2 months on new contract

My phone was booked in for a warranty assessment on the 26 May after my new i phone 6 (2 months old) touch pad was faulty. This was supposed to take 7 working days and I should have been issued a new phone or the current phone repaired etc. After dealing with the Cresta branch (where I booked in the phone) they struggled to update me as a result of the strike etc. After having a complete freak out at the branch last week they informed me the device could not be located at the repairs centre in Midrand. The manager at the Cresta branch has since been very helpful in trying to chase this matter but he gets very little response from MTN head office and feedback after they have now said they will replace my handset with a new one.