I suggest you go after the publisher of the flyer. There's no obligation on the part of the printer to establish copyright (they just print). The designer has a responsibility... but probably no money.
The biggest advantage of the small claims court is that you dictate when and where (to a large extent). This can be expensively inconvenient for anyone having to engage counsel. :wink:
But I'd expect them to ask what you did about it. If you wrote to the publisher (and can prove it) and received no reply, it is very much in your favour. It's also helpful if you have witnesses as to you having made the original artwork.
Of course, if they got their own artist to create a similar scene (assuming it's a real place), none of the above applies - theirs is a new, original artwork. If they modified yours, without permission, it's plagiarism and theft of IP.
E.