Unprofessional MTN

I bought my Tablet in March and than it suddenly stopped charging around July so I went back to the MTN store which I bought it at and they booked it in and said it will take up to about 2-3 weeks to be done than I'll get my phone but till date I still haven't received my phone back, no one is saying anything I went to the store to find out what's going on when I showed them the serial number that was written on the paper they were like I should bring in the phones imei number whereas when I did the booking they had said when I come through I should bring in the serial number and I feel this is really unprofessional and inconsistent and as for a client who has bought that phone in cash I get such a service even from the manager herself she didn't even seem to be very assisting as they were already preparing themselves to go home but can't even spare a few minutes to assist a client.

I would like feedback about my phone as it's over a month now without receiving any info about my phone.