MTN data purchase refund

My mom, a pensioner was victim to a data and airtime theft. The ******** did not have time to transfer the data he had purchased out of her account - I called and explained the situation to MTN, requesting a refund on the data purchased to the value of R19,000. But was told they are unable to refund, the charges have not been invoiced yet as its been less than 24hrs since the ******** purchased the data. The data has not been used. I would like to know why she is not able to get a refund (reversal of this data purchase).

At this point I feel MTN is little more than an accomplice in this due to their heartless unwillingness to assist in a pensioner being taken advantage of. Especially since this has not even been billed against her account yet.