Do you think I got screwed, or is it just part of the hobby?

What oil is being used in it??? full syn...semi-syn....mineral???? What grade of oil???15W40...15W50...15W60...20W50...25W60????
Have you been loading up the engine ( driving in top at 30mph and hold it flat till 60 mph, back off till 30 again and do it all over)????
A "rapping noise".....piston???.....crank/rod hitting dip stick???