As indicated in the following section, your transaction appears to be covered by Regulation E.
“Sec. 205.3 Coverage.
(b) Electronic fund transfer. (1) Definition. The term electronic fund transfer means any transfer of funds that is initiated through an electronic terminal, telephone, computer, or magnetic tape for the purpose of ordering, instructing, or authorizing a financial institution to debit or credit a consumer’s account. The term includes, but is not limited to—
(i) Point-of-sale transfers;
(ii) Automated teller machine transfers;
(iii) Direct deposits or withdrawals of funds;
(iv) Transfers initiated by telephone; and
(v) Transfers resulting from debit card transactions, whether or not initiated through an electronic terminal.”
The following section further clarifies the rules.
“12(a) Relation to Truth in Lending
1. Determining applicable regulation.
i. For transactions involving access devices that also function as credit cards, whether Regulation E or Regulation Z (12 CFR part 226) applies depends on the nature of the transaction. For example, if the transaction solely involves an extension of credit, and does not include a debit to a checking account (or other consumer asset account), the liability limitations and error resolution requirements of Regulation Z apply. If the transaction debits a checking account only (with no credit extended), the provisions of Regulation E apply. If the transaction debits a checking account but also draws on an overdraft line of credit attached to the account, Regulation E’s liability limitations apply, in addition to §§226.13 (d) and (g) of Regulation Z (which apply because of the extension of credit associated with the overdraft feature on the checking account). If a consumer’s access device is also a credit card and the device is used to make unauthorized withdrawals from a checking account, but also is used to obtain unauthorized cash advances directly from a line of credit that is separate from the checking account, both Regulation E and Regulation Z apply.”