The bank in question is not concerned with buying or selling of goods or even with the reason and cause as to why the card was swiped. It is not bothered or concerned with the quality, price, nature, quantum etc. of the goods bought/sold. The bank merely provides banking services in the form of payment and subsequently collects the payment. The amount punched in the swiping machine is credited to the account of the retailer by the acquiring bank, i.e. HDFC in this case, after retaining a small portion of the same as their charges. The banking services cannot be covered and treated as services rendered by an agent for the principal during the course of buying or selling of goods as the banker does not render any service in the nature of agency.