Many people hear that a request is denied and start arguing on the spot. A calmer approach is to treat the denial as the start of a short paperwork trail, and to keep that trail complete from the first phone call onward.
Before you hang up
Ask for the request or reference number and the name of the person you spoke with, then write both down along with the time and day of the call. Ask what reason was given and whether that reason will be sent in writing. If a letter will follow, ask how it will be delivered and how long that usually takes, so you know when to start watching for it.
The technician visit, if one happened
Some denials come after a technician has already been to the house. If yours did, ask for a copy of the visit notes or work order. Write down the technician's stated findings in your own words the same day, while they are fresh. A service call fee, the charge you pay at the door for a visit, may be due on a visit even when the request is later declined. Check your contract's wording on that point and keep the receipt.
The written reason
When the written reason arrives, check that it names the specific part of the contract it relies on, not only a general statement. Compare the stated reason with your own notes and the visit record. Any mismatch is worth a written question back to the provider, sent by letter or email so there is a record.
Deciding your next step
Find the appeal deadline in the contract and mark it on your calendar the day the letter arrives. Gather what the contract allows you to send, such as photos, earlier repair records, or a copy of the original request. Send it with the reference number on every page. If the process ends without the outcome you expected, the contract's dispute section and any outside review it names are the next places to look.