For many different types of credit and debit card transactions, an authorization occurs before the actual purchase is processed. The authorization happens when Grab initially contacts the card holder's issuing bank to check if sufficient funds are available for the actual transaction.
Authorization for incomplete booking will be carried forward to the subsequent booking. This is the situation you have encountered.
For booking Code: A-39S75NIWWIRW
The authorization amount of SGD 32.30 was made for your booking A-39S64BLG2FAK which has been cancelled. This pre-authorised amount was carried forward to the subsequent booking A-39S75NIWWIRW that you made later at 02 Apr ‪2022 17‬:50
The final fare for your JustGrab booking A-39S75NIWWIRW is SGD 34.20 .
Therefore, you were charged an additional SGD 1.90. You may verify your booking payments on Grab app by viewing GrabPay Recent Transactions section.