If nothing was unclear or difficult, say so. Skip questions about steps you did not experience; use not applicable where appropriate.

Which issue remained unresolved?
What contact route was unclear?
What follow-up information would help?

Author notes / illustrative keys where applicable:
1. An unresolved issue identifies what remained after completion and requires an appropriate contact or review. Clarify scope without assuming feedback proves a service failure.
2. An unclear contact route reveals whether customers can identify the right source for questions after completion. Explain actual support scope and official references, without promising ongoing service or interpreting guarantees from feedback alone.
3. Helpful follow-up information identifies the next step or contact customers need after delivery. Explain verified support arrangements without promising coverage beyond actual conditions.