In one of the emails from WL it stated: If you want to cancel order put "CANCEL ORDER" with you order number in the subject line. It may not have been worded exactly like that, but it was close. Unless they see "CANCEL ORDER" in the subject line they will not respond. It gets a quick response when you do it the proper way!
That being said, the OP apparently put conditions on his refund. They basically ship out assuming it will meet the specifications (which it most likely will not). So since you said you would accept a laser that met specifications I assume that was why they shipped it out. If it doesn't meet specifications you can always send it back to them to be "fixed". But that implies you have some way to accurate measure and prove it doesn't meet the specs, and even if you can do that you then have to send it back and deal with them all over again. Just by playing the numbers most people won't bother with them if they have even a marginally functional laser.