I agree its the spokes or lacing pattern, Can't see in the picture and I believe they are 14ga spokes.
First thing first, get the LBS to get it right. Your bike is under warranty http://www.specialized.com/us/en/bc/....jsp?gold_ses=.
If the LBS can't fix it then contact Specialized to fix the issue, looks like the wheels are under a 1 year warranty.

If the rear is the only issue and I am guessing it is, then just spend the money on that one to be re-laced.

The shop should make good on this, even if you weight 450 lbs (I HAVE NO IDEA WHAT YOU WEIGH) and they said I told you so.