If you send in your coins using the 15 day turnaround shouldn't you get your coins back within at least a MONTH!!

I send in alot of coins and I alwayse use the 15 day grading but I alwayse get my coins about a month to a month and a half after they have recieved them. I understand that they get alot of coins in but I pay $30.00 plus the Extra shipping cost to get them back quicker. So I should get my coins in the time that they advertise for that turnarround period which is 15 to 17 days. I mean that is what I am paying for right?? I would be affraid to send my coins in with the 30 day turnarround there would be no telling when I would get my coins back. Does anyone else have this problem or is it just me???