CANNOT LOAD DATA BUNDLE ON NEW CONTRACT

I did an upgrade on my contract last month to a Mycall contract that allows you to purchase additional airtime or data through prepaid once the given monthly airtime or data is exhausted. I bought a R100 voucher and loaded it, and it doesn't allow me to purchase additional airtime. I called the call center and was given a ref no: ***. And nothing has happened since. I tried calling the call center several times, and as usual whilst holding for an operator, the call gets cut- I'M NOT SUPRPRISED, AS THIS IS ALWAYS IS THE CASE, WHEN CALLING MTN CUSTOMER SERVICE ON 808!. Can this urgently please be resolved as the R100 I loaded is been depleated at a very fast rate due to out of bundle charges. And lastly the *141*2# functional also does not allow me to convert the money to data bundle.