Service indicators work out when they think the car needs a service based on a number of parameters, such as (some or all of);
- How many miles the car has travelled;
- How long ago the previous service was
- How many cold starts the car makes
- The condition/viscosity of the oil.
- Etc.
In a text book situation, you travel 9000 miles in a year, for example.. the car tells you it needs a service.. you get a service and then repeat.
What happens in real life is that you travel 4000 miles in a year. The car doesn't "need" a service but the dealer told you you should get it serviced every 12 months, so you service it. The garage doesn't or can't re-set the service indicator, since it's not indicating a service is due.
The car drives along and doesn't know it's been serviced. So another five or six months later, it thinks it's now gone 18 months and has travelled 13,000 miles so it must be due a service, right?
With your low miles, the service light may have been triggered by a lot of short journeys (lots of cold starts relative to the mileage) but I don't think 3300 miles should trigger it, even if you've never had a service. It's more likely been triggered by how long it's been since it thinks it was last serviced.
Without knowing the 500 system, and if I was designing it, there should be an option to set the service indicator even if the service indicator isn't lit... so the car logs that it had a service in August 2021 and 2300 miles. If the 500 has a system like this, then it should have been re-set and probably wasn't. If it doesn't have this system and can only be reset once it's lit, then a) that's not very good and b) the garage owes you a free reset since they would have re-set it if they could and they obviously didn't reset it if they could have but forgot.
Not sure what the "coupon" is. Is that something in your service plan that's been "used" when you had the service?
Ralf S.