Request cancels payment for given payId.

It should be noted that on the day of the transaction partial amount should be cancelled only one time.

If necessary, you must apply to the bank to return the remaining amount.

You can refund part of the amount in the following days after the transaction.

In case of pre-authorization preAuth = true partial amount can not be canceled before payment completion.
To partially refund the amount, use the confirmation / completion method with the amount to be authorized, in which case the remaining amount will be automatically returned to the customer.