We have a lot of questions recently along the lines of the following:
I sent coins to service X which was supposed to credit them to my account (or deliver a product, etc). The transaction is confirmed but they haven't credited my account. What can I do?
In principle such questions could be closed as "customer relationship" but I think a major problem is that askers don't realize that this is a customer relationship question; they think there might be something they can do unilaterally. So perhaps we could have a canonical question along these lines, with an answer that explains why there is nothing to be done except to try to work with service X.
Some topics that might be useful to address:
How to see on a block explorer that the transaction is confirmed
Why "confirmed" is not necessarily the same as "acknowledged by recipient"
Whether it is relevant that the output shows as "spent" or "unspent" (it isn't)
Possible reasons why the service might not be crediting their account (incompetence, software bugs, inadequate customer service staffing, expired receive address, outright fraud)
They should be prepared for the possibility that they might never be able to get their coins back
Does this seem desirable? Anything else that should be in such a question?