Apple payment

I had asked to upgrade my icloud storage capicity to 50 GB and added my credit card to pay 3.69 SR per ,onth. The amount of 3.69 SR has been deducted from my credit card balance, and after awhile, another 32.99 SAR has been deductred. Please note that this is not the first time this is happening, it happened two or more times before and that is why i deleted my credit card details from your system. Now as i provided the details again, same issue happened. Please advise why aditional 32.99 SR has been deducted?