Do shops still sabotage cars for profit?

i got a long one but will try to keep it short. i have / love a 2001 hyundai sante fe. i am the original owner. 100,000 trouble free miles. last year the transfer case went, they replaced it free at dealer. driving in the snow 2 days later the alternator went. turned out they didnt put the lower splash guard back on the car. they replaced the alternator free. in sept the #2piston pooped the bed. turns out i opted for the 12 year 120,000 mile warranty on the drive train so the motor was covered and after 8 weeks (yes thats not a typeo) i pick up my beloved car. i go 2 miles feel a heave vibration over 30 mph. go back to a now closed service dept but leave the car anyway. next day get a call that the ball joints are bad that what the vibration was and they want $450.00 to do the lower right and left. i say no thanks and a trip to napa and $60.00 later i'm replacing them in my non heated 18 degree garage. i do the right side (pretty bad shape) go for a warm up / test ride to find no difference in the vibration so i start the left. I notice there is no play what so ever in the wheel and start to look around. thats when i saw only 3 of the 4 rear drive shaft bolts in place and they were only started by finger. the shaft moved about 1.50". pissed off i tighten the 3 bolts and look around the car alot closer to find several bolts / nuts loose / missing and i was 2 quarts low on oil. keep in mind i have only put like 30 miles on the car since the engine replacement. now the big moment sure the vibration is fixed, all bolts tight, a new right side balll joint and 2 quarts of oil and here i go to fill er up and enjoy wy now 10 week absent truck. i made it 8 miles and BAM!! the f-n motor went again. so its back at the dealer (only one local) and i am waiting for the bull crap excuses. aaah... thanks for listening, somehow i feel better.