It may be that you need to change dealers. First off, have you been spraying the chain with one of the many available chain lubricants every 200 miles or so? The chain and sprockets should be cleaned as often as practical too. If not, chain and sprockets will wear quickly and need frequent adjustment.
As for the oil, these bikes don't usually use significant amounts unless there is a leak or the engine has lots of miles on it. I would be willing to bet that if you don't see any signs of a leak, the dealer mechanic filled the crankcase when they changed the oil, then forgot to refill it after starting the engine and filling the oil filter. Now, that is just unforgivable.
