Get the landlord in there so they can see this issue. IF YOU DON'T WHEN YOU MOVE OUT THEY MAY SAY YOU DAMAGED THE CARPET AND DID THIS.
Sorry to yell but seriously...I have had landlords try to charge me for damage to their apartments for something "I" wrote down as an issue on the walk through they did with me "before" I moved in.
One time I rented an apartment in town and as I walked through with the guy I pointed out that there was a circular stain on the carpet that looked like someone had been varnishing the end of an open barrel then turned it upside down. He told me he'd have the carpet cleaned and take care of it. I wrote it down on the paper I had. When I went to move in it was still there. I mentioned it again. He said the cleaner had been there and said they got it up. I said they didn't.
When I went to move out he hit the roof over the stain. I pulled out my copy of the lease and walk through and pointed out the note I wrote about it. He still refused to give me back my deposit because he said they got it out. I pointed out that it was exactly the size, color, shape, and location of the stain in the walk through.
He decided I still couldn't have my deposit back because they were going to have to paint and clean the carpets before they could rent it to someone else.
I lived there over 5 years, I would have expected them to have to do that due to basic wear and tear on the apartment anyway.
This apartment was the only situation where I did not get at least half of my deposit back. Usually I get 100% back because when I move I made sure the place is the best I can make it.
So make the landlord take care of this issue. Find a dealer that sells this kind of carpet and go to the showroom and feel of it. Does it feel odd? Then maybe it's the carpet's fault it is weird. If not then it's likely needing to be cleaned.
Some carpets can only be dry cleaned, they have chemicals they sprinkle onto it then run a super strong vacuum over it.