Bad customer service

I went to MTN on the 9th of February Maponya mall store and I was assisted by Gontse with the contract deal that I wanted... Everything went well and he advised that my 1st payment will be due in March, okay and he never told me about any pro-rata that will be charged, to my surprise month end of February I got an invoice that I'm in arrears, went to the store and he assisted with that and my sim was reactivated, month end of April I get another invoice that I'm in arrears for the month of February again and my debit order didn't go through for March, I don't mind paying for March but now I want to know, why wasn't I told that I have to pay for February and I'll pay abit extra for the prorata.. Went to Southgate and they explained everything to me, but now I want to know why some of your stuff members give us invalid information, now I'm in arrears my sim is blocked, please assist and on top of that I was told both of my phone are insured until it was time to claim and I was told they only insured one phone and not the other one... Maponya mall branch is the pits and that Gontse guy is the worst