A self-serve copy example for this shopper question: Can I cancel my order? Use it as drafting help for inside a short pre-purchase answer without creating unsupported promises.
This is educational drafting material, not legal advice. Match the wording to the store's actual policy and operations.
Put the short version inside a short pre-purchase answer. If the answer has exceptions, link to the full policy instead of trying to fit every rule into one sentence.
Good trust copy should reduce confusion without making the store sound bigger, faster, or more certain than it really is.