contract sim has been switch to a pre paid and im paying for a contract still

A couple of month could be two or so i wrote about vodacom and that they were taking money from my account for two contracts that problem is solved,now after they fixed i cant phone from my phone or use my air time that i have paid for this is on both my numbers,i have emailed them a number times once a day when i have time and not even nothing it shows read receipt and that it i leave my phone at home because my son comes home now i had to go out of my way to buy a nother sim and put air time on that because the contract i have i cant use .This is very frustrating im due for a up grade but i will not be taking out another one with these endless problems.it seems as if they made my contract sim into a prepaid sim