Taxify stole money from my account

i used taxify on saturday 04/08, my trip was R40.00, later on i got an sms from Absa saying an extra R100.00 was debited from my account, when i inquired with Absa, i was told it's Taxify, i sent them a message to enquire about the transaction, a guy by the name of Carl tells me it's their way of validating my card, why do they take money from my account without my authorization and tell me they are validating my card, was the trip amount not enough? now i have to pay extra charges to Absa as they had to block my card, & i have to get a new card, and i pay for that.