MTN stole my airtime

I purchased R40 of airtime via my banking app for another number, I found out that that person only received R20. When i contacted the call center on 135 (which took 20 minutes), the consultant told me that she couldn’t help me because I would need to phone from the other persons phone. Well, I tried to call from the other persons phone, and when I try to press 0 to speak to an “MTN Service Champion”, I’m told that I have selected an invalid option.

I value my hard earned money and I will not let go easily. I await your response.