As a previous poster mentioned, the shop does not fit the chain during the pre-sale build (PDI). It’s fitted on an assembly line in Taiwan.
The PDI on a Specialized bike involves cabling the brake/gears, fitting front wheel, seatpost, pedals, bars into stem, and setting up the bike.
You would be within your rights to ask the shop to change the chain for a new one (as the original failed) perhaps KMC, and the shop can easily get Specialized UK to credit them for this cost.
The mark to your frame is one of those things. Again you’d be within your rights to ask to have the bike replaced, but its going to get scratched sooner or later..I would not bother.