Supply and exhaust air of the decentralized ventilation switched - cleaning?

Merry Christmas first of all

Now my question:

When changing the external filters of our central ventilation system with heat recovery for the first time, I unfortunately had to find that the intake and exhaust openings are swapped, i.e. it is diligently filtering the exhaust air and the supply air enters the system unfiltered. Can I demand a cleaning of the system from the contractor in addition to the defect rectification (he will only replace the "end pieces")? (The system has currently been running for 6 months and in the meantime the street was also worked on, so there must have been a lot of dust in the air)

First check how much dirt is in the pipes before you slam on the table. But I also suspect that a pretty nasty layer of dirt has formed in the pipes over the past 6 months....

Since the central systems also have filters in the device for supply air and exhaust air... nothing should have happened in the house at all... and you can also clean the hopefully relatively short intake pipe yourself... after 6 months there should be hardly anything in there even if the street has been worked on, etc.

I think the same will be told to you by the general contractor... so there isn't much to make a fuss about...

The pipes are not that short; they go under the floor slab outward or inward. Length up to the end piece approximately 9 meters.

So if there is no dirt to be found in the first meter, I suppose it will also not be dirty after 9 meters.. Or am I perhaps mistaken?

The pipe goes straight down for 2m, there is nothing to see there. I will inquire with the manufacturer in the new year to see what they suggest.