that could be a very important/expensive lesson you've just learned; NEVER TRUST THE DEALER! Just because they SAID they did everything properly, it is still up to you to make sure something as simple as checking the oil level is correct.
I hate to sound like a hard-***, but that's like riding around with a tire half-flat, underinflated by the dealer but never verified by the owner ( yes, I've seen that...my neighbor's RK). You need to get it in to someone reputable ASAP, and get things checked out. Be prepared though; that could be an expensive lapse on your part