We make things simple
The screen has stopped responding in one corner. The authorised centre is across town and quotes you a figure that makes you blink. The shop near the market says he will do it by evening for much less. Both answers โฆ
The washing machine stops draining and you ring the service centre. Their first question is the date of purchase. You are fairly sure it was two years ago, or possibly three. Somewhere in the house there is a bill, and โฆ
The screen cracked, and you remember the salesman saying one year warranty. So you carry it to the service centre feeling reasonably safe. They look at it for four seconds and quote you a price. Nothing has gone wrong, except โฆ