I have owned both the Vandersteen 2ce Signature and the 1c, and I've never had any problems with the lower frequencies. Even with a modest amp (Audiolab 8000S, Creek 4040), they never failed to provide me plenty of bass slam and gorgeous mids. For the price, they are fantastic speakers.
I'm just curious - how did you detect that the courier damaged the tweeter? It's not visible through the sock.
Is it possible that the internal wiring has been damaged when it was transported back from repair? Vandersteen uses a very inflexible solid core wire from the connector to the crossover, could it have somehow been jerked out of it's soldering?
At this point, my only suggestion would be to bring the whole setup (including amp and cables) back to the shop that repaired it to double check where the problem lies.
Or if you're up for some testing, you can try this simple test:
Try connecting just 1 speaker to the left channel of the amp, play a track and listen (just 1 speaker, the other should not be connected at all). Then connect the other speaker to the same left amp channel and listen to the same track. If they are working properly, both sides should sound the same. If 1 side sounds softer, then that speaker has a problem.
Best of luck!