NewbtoRC, give these guys a break -- they didn't build the motor, or the plane, & they are helping you to overcome your problems & they are entitled to be paid for their time & materials. So far I haven't seen anything in your post to get yourself upset at the LHS about.

It is reasonable to expect that the customer can operate the equipment competently -- it is also reasonable to expect to pay for services. I doubt if there is anything actually wrong with your engine -- just that you are not really "tuned" into it yet yourself. Perhaps there is something being lost in the message you are sending to us -- give us more details.