Acme headliner Rock Auto

I purchased a headliner from Rock Auto the plastic foam backed one in black made by Acme.
I had it installed 6 months ago, I noticed yesterday the headliner is drooping, I had it installed by a professional, has this happened to anyone else and what might be causing it.
I paid $250 to have it installed, even if they warranty it I’m screwed, I have a broken neck or I would install it myself.