Assistance on an incorrect voice purchase.

Please assist, i usually buy R12 all network daily 60 minutes voice minutes. Today i came across one saying R59 for 30 days and i thought its a great deal. Only to find out that is 50 minutes once off and i thought its 50 minutes daily allocation for 30 days. I only used 5 minutes as i made a call before i saw the sms. Kindly assist by reversing this please, i bought something i thought was a great deal but actually not. I've been a loyal customer for around 20 years on this contract and would really appreciate your consideration on this mater. I also have Fibre contract with you. My number is ***.