This is breeding season and a lot of breeders are really busy. I know not really a good excuse.
Is this snake a male of perhaps breeding size and a morph that would be good to get a lock from with a female or two before shipping?
If you don't get it by the end of 4 weeks I would ask for a refund, give him a neg on the site you bought from, and if he actually has a business name I believe a review section exists on this web site. If not I believe you can still review him in that section!