My girlfriend says she can see stains in the carpet and a few look yellow and i can only guess at what that might be.They told my gf they would have someone come and vacuum last night and then at 630pm they called and said they couldn't and that she needed to go do it.

My rule for rentals is...Clean concrete subfloor....stained concrete.Dirty concrete subfloor....tile.Wood subfloor....laminate.Wood bathroom or kitchen subfloor... ceramic tile or linoleum.  

Mold stains.

I use a brown cinnamon carpet made of recycled plastics (great rental as it repels stains) with a nice pile installed over a 6lb pad.  

Your cleaning of carpet may stand up if you have pictures showing the stains were there and removed.

We stained and sealed them for about 50% of the cost of the off the shelf prefinished cabinets.  

People expect a perfect house - spick and span without any loose doorknobs, creeky doors, stained carpet or any other ideosyncracies. 

My favorite is stained concrete.

However, they left some rust stains in the corner of the bathtub (what looks like from a metal can they had there), I've tried CLR, Lime away, bleach, etc. and I cannot get this to come out. 

Quality paint, stains, cabinet and counter top resurfacing all dirt cheap.