12 CFR §1005.34

1. (a)Sender right of cancellation and refund. Except as provided in § 1005.36(c), a remittance transfer provider shall comply with the requirements of this section with respect to any oral or written request to cancel a remittance transfer from the sender that is received by the provider no later than 30 minutes after the sender makes payment in connection with the remittance transfer if:
   1. (1)The request to cancel enables the provider to identify the sender's name and address or telephone number and the particular transfer to be cancelled; and
   2. (2)The transferred funds have not been picked up by the designated recipient or deposited into an account of the designated recipient.
2. (b)Time limits and refund requirements. A remittance transfer provider shall refund, at no additional cost to the sender, the total amount of funds provided by the sender in connection with a remittance transfer, including any fees and, to the extent not prohibited by law, taxes imposed in connection with the remittance transfer, within three business days of receiving a sender's request to cancel the remittance transfer.