When we first checked into this Airbnb the sheets on the bed were dirty. I called the owners who, while coming out later that night to change them, were very rude and insisted that the sheets were clean and it must just be "an old stain".
There was also almost no toilet paper in the bathroom, we didn't notice until after they had changed the sheets so just went and bought a roll ourselves.
The location is great, right next to the Old North Church on the Freedom Trail, but that didn't make up for the customer service.