Bought a new engine for my 98D,need input..

Hey all,need your input on a few questions im having after just replacing my ENGINE and OIL PUMP!..$3,500 Later..So i buy a used 318 engine with 66k miles on it, also bought some Gibson Headers and i already had a Magnaflow exhaust system along with a SuperChip 3715,everything is badass! its just the WHOLE ordeal PISSED me off...WHY did i have to go through spending almost 5k, on a rental car ,towing charges and fixing MY Engine problem "ENGINE 78,000 was on it....it gave @ 12am in the middle of know where, comming home from losing $500.00 in gambling..lol serves me right >)
Anyways..it came down to my oil pump stopped working, and that of course made the engine blow...booom it went. had 3 buddies with me @ least when it happened...I call Chrysler about it,cant help they say...stupid,just stupid that i have to buy a engine becuse of a faulty part...So...what do i have to do to keep it from not happening again?

Also...The place that fixed the durango "put the engine in" is lagging big time on getting me proof that i bought the 66k engine..what do i do if they cant come up with it "proof" or they say something stupid,like oh its the 90k engine..heres 500.00 back...can i return a engine..? or do i have to sue...?


your input would be great...Thanks