Bad Customer Service

On the 14th I called MTN to upgrade, they told me the phone will be delivered on the 16th. On the 15th my line was barred (how coz im a TOP UP customer)& I couldnt make calls.On the 16th my phone was delivered with a new sim card, I called the call centre to activate and do sim swap, the guy I spoke to said it will be active in 4 hours. 4 hours went past and another day went by without being able to use my phone. Today the 17th I called the call centre and the guy I spoke to said he will open my line which he did but opened the line for the old sim card and not the new one. Which means I cant use my new phone coz the size of the sim is not the same. I called the call centre again only to be told by this lady that I need to go to the store and get my sim swap done from the store. Now, what is the use of upgrading telephonically if i cant get things done the right way? the reason i upgraded telephonically was to avoid going to the store. The call centre agents are not useful because they fail to assist instead they are telling me different stories to get this sorted out. I missed 2 days of business because i didn't have access to using my fone which is a problem from MTN and not me.