Hello,
Sorry to hear about your new floor!
The best solution depends on the extent of the damage. If it's a small dent, you might want to consider letting it be. Try covering it up with a rug or piece of furniture.
If you wish to repair, wood putty is a good option. But do take note that wood putty is not very hard, and can flake off with time and traffic.
I would usually not suggest replacing just a single piece of parquet. The cost is disproportionately expensive, and the colour of the replacement piece could be noticeably different from the rest of the floor. Inevitable as wood is a natural material.
Good luck.