I would like for them to just reverse my payment for the second purchase because it was their App that gave errors, it wasn't me who just bought twice, the error message stated that it failed and I should retry

I used the Capitec app to purchase an electric token, after I made my purchase the app gave me an error that said "Error, force close and try again" so I force closed the app, retried to buy another electric token, it failed again and after 2 min I received two SMS's with both tokens, so I called Capitec explained that their app failed twice and deducted twice out of my account and they just refused to help me. I have debit orders that gonna bounce because there app failed.