there is no cancellation option for the end users after payment is made. in case of duplicate payment, parent/student, kindly approach admin or finance or accounts department for refund with proof of the transaction reference/ your bank statement. refund will be processed within 10-15 working days, respective payment gateway will send back to the issuing bank [user’s card banker] in batches for processing, which should approxixmately take 8-15 working days, depending on issuing banks policies.