I hired a painter decorator back in July. His original estimate was for the work to take 4 weeks, but because they did the job slowly and had to redo some bits, it took closer to 8. I did ask for some extra work to be done, as they went along - a change of paint colour on a banister and on two doors. Also after there was a problem with the finish in the hallway, I agreed for that to be reskimmed and painted again. I also asked whether they would fill one crack inside a cupboard and paint a bookcase, which the guys agreed to do as they were there for so much longer. At the end, I received an invoice for the original quoted work and a separate invoice for the extra work, around £5000 in total, which I paid minus £50 which I held back for some snagging, which they never returned to do so I kept. That was all settled back at the end of September apart from the £50.
Today I got an email out of the blue from the guy saying that he has now paid his guys and he has made a £2000 loss on my job. So he has sent me an invoice for an l additional £1900. I am really taken aback by this. Is he just trying it on? Does he really think I'm just going to give him an additional £1.9k because he asks for it, two months after he'd sent me a final invoice which I paid promptly minus the fifty pounds? Should I be worried?