MTN Momo not paying our winnings

Ithuba, I am writing here to complain about banks or financial institutions that have the lotto option in their apps or one of the things you can do on their banking. I played powerball on Tuesday and hoping that my winnings will be credited back to my number as I played with MTN Momo. Normally I would have an sms to tell me that my account has been credited with R5 from lotto. And now that I got 3 numbers right it is now the 2nd day I am waiting and nothing. I wonder how much else has been taken from me because I rarely check the numbers if I won or not. Is there a way to deal or claim this since this is an online app with no contact details?