Final answer:
The manager's resolution is an example of an unstated guarantee, a form of customer service where satisfaction is provided despite the lack of a formal policy.
Step-by-step explanation:
The manager's resolution to the situation described would be an example of an unstated guarantee. This type of resolution is comparable to instances where, for example, movie theaters may offer refunds to displeased customers despite not advertising such a policy, or restaurants may allow dishes to be exchanged or offer discounted bills to unsatisfied customers without explicit guarantees. In the scenario provided, the manager stepping in to resolve the issue where the customer did not receive a receipt, and the clerk cannot issue a refund, shows the business's flexibility and commitment to customer satisfaction beyond rigid policy structures.