Above an image from the internet, it says it's for a Citigo.
Have you noticed that yet, if not don't worry about it. All modern cars now all have oversized wheels and wider tyres so more rubber debris in the air and down the drains, more diesel cars after the 1990s con so more crap from their exhausts than previously and of course more cars on the roads overall, many doing very sort distant journeys where they don't fully warm so running well below full efficiency and cleanliness. But if you've not noticed anything yet then don't worry about it.
The air-con is useful for cooling a hot cabin in summer and clearing condensation caused by various reasons, You must be young, it's not that far back that small cars didn't have air-con and going back a bit you'd have to have a luxury car to have it or it be on the list of options.
We survived many decades without air-con in summers and winters, it is possible, hotter now for many reasons and cars have to be locked and sealed up, and with better sealing, so hold more cabin heat and for longer, also even a Citigo is a bigger car with probably(?) more glass on it than earlier small cars so possibly gets more solar gain (heat from the sun) and more sealed so holds the heat in - but you can overcome most/some of this with a little effort. If you need advice on such things just ask.
Normally setting the heater to cold (and keeping the recirculation off) will get cold or cooler air from outside into the cabin, if need the output to the cabin can be speeded up and assisted by turning the blower on to 1, 2, 3 or 4.
If you need to know more about operating your heating/cooling system you (and your mechanic, he's the one I worry about) then just read the Owner's Manual for your car for this and other stuff you need to know about your car, free Skoda pdf download free here. - https://manual.skoda-auto.com/004/en-com/Models
Again, if you read and when required refer to the Owner's Manual you'll learn and know a lot about your car and how to maintain and drive it and could save yourself lots of time, hassle and money by sometimes avoiding garages and mechanics. A lot of servicing, maintenance and repairs just boil down to clean and lubricate (including electronics and computers), some/much of it is so simple even I can do it, so you could if you wanted, including most (possibly all) of the service your mechanic might have done.
Have you got a list of what was done in the recent service as most services are far from full for the whole car and many services are no more or little more than a change of engine oil change and (hopefully) engine oil filter and a look around for more chargeable work. There's a lot more to a car than just the engine oil, the engine isn't the most important thing, brakes, steering and suspension (all three include tyres), then safety electrics (lights, horn, blower, wipers perhaps) and glass (windows and mirrors) - see and be seen.
Start new threads if you want or need to know about other stuff and as you've seen posters here will help you.
HTH.