Bad Service

I did an upgrade with MTN Festival Mall on the 25th of Aug they gave me a new sim card and advised me that it should be working within 24-48 hours its the 2nd of Sept the sim card is still not working I cannot make or receive any calls I called the mtn call Centre and they told me I should go back to the store so that they may check the sim card, I called the store and advised them I cannot come in because its time consuming as well as money for transport for me to go there they logged a USD 549440 and told me I still have to come to the store when I eventually went there they told me I have to wait a further 2-3 working days because the USD is not resolved. I went there on Friday the usd was logged on Thurs its the 4th working day today and my sim card is still not working. MTN convinced me to upgrade so that they can retain me as their customer and then I get this sort of treatment Im sitting with a sim card that hasn't been active since last week and all im getting from MTN is just postponed dates. I might as well cancel this upgrade and move to another network. Should this not be resolved by COB today then I would like to cancel this upgrade.