MTN momo *****sters

I bought R100 electricity om the Mtn Momo app. And got a voucher. I then bought another R120 Electricity on the MTN Momo App and they send me the exact same voucher no as before. I emailed them and the lady that responded processed to explain to me like I am an idiot how ro put in electricity. I replaced telling her that how can I put I the same voucher and telling her I want my R120 back then no reply after that. I complained on social media no reply. MTN momo I want my money back