Most dealers will not refund you in full unless you order from them a ton. They most likely will say your SOL or refund you their profit, which is usually around 20%. But just message them and ask them what their policy is. They should have known not to send FIVE in one package!
5 watches at one time - I think that's just asking to get seized. You want to keep the packages under 10 pounds and I try to only do two watches at a time.
Longest I've had a package in customs was two weeks, then it was released. Had a couple packages seized and got a letter within 30 days after they were taken. Don't call USPS or anything it will raise flags. Also, if you get the letter, ignore it and throw it away.
Good luck man - I hope the outcome is in your favor.