post https://app2test.infiniaweb.com/infinia_api/v1/accounts/movements/refund/
Only deposit movements with operation_type = CREDIT are eligible for refunds. Please note that a refund may still fail after being initially marked as SUCCESS, in such cases, you'll receive a callback with status = FAILED.
To refund a Payin, please use the Create Refund endpoint from Payins.
To simulate a failed refund in sandbox, you can create a deposit with amount = 101 (see the Create Deposit endpoint for details).