Handle warranty claims against the exact unit a customer bought
When a customer comes back with a faulty phone or laptop, you can now find exactly what they bought and check its warranty.
Each unit's warranty starts from the day it is sold, so you can see straight away whether it is still covered. If the warranty has expired, the claim is blocked and you are told the date it ended.
Raise the claim against that unit. Only one open claim can be raised for a unit at a time, so nothing is duplicated.
Then resolve it as it suits the customer: repair it and return it, replace it with another unit in stock at your store, refund the sale, or reject the claim with a reason. Every step is recorded in the claim's history, so you can answer the customer's questions later.