A covered repair moves through a sequence of steps, and each step usually produces a document or a reference number. The sequence and the names of the steps differ by contract, so the claim section of your own contract is the map. This guide describes the common shape so you can check for missing steps.
The steps in order
You report the problem, and the provider confirms the contract is in force on that day. The provider gives a claim reference. A diagnosis is authorized, and the technician reports what failed and what the repair needs. The provider authorizes the repair, sometimes with an authorization reference that must appear on the invoice. The repair is done. The invoice shows the authorized work and any charges outside it. The file is closed with a written record.
Where the paper goes missing
Most gaps appear between the diagnosis report and the repair authorization, and between the invoice and the closing record. At each of those points, ask for the document by name, note when you received it, and keep it with the contract. If a step has no paper, say so in writing and ask for it.
How to use the references
Put the claim reference on every message you send. Check that the authorization reference on the invoice matches the one the provider gave for the repair. A mismatch is a question for the provider to answer in writing before anything further is billed.