Checklist for Marketplace cancellation and refund requests?

Is there a guide or checklist for what should be gathered before submitting a cancellation and refund request for a private or multiparty private offer?Specifically, what does Microsoft need from the vendor, the customer, and us as the reseller? I’m looking for required IDs, reports, refund details, consent language, and any steps that need to be completed before opening the ticket. The goal is to submit everything correctly the first time, reduce back-and-forth, and help the request move faster. If anyone has a guide or standard process, I’d appreciate it.