Do shops still sabotage cars for profit?

when i got my roadrunner a few weeks ago it had brand new tires on it yet two dys later the tired was flat. so i took it to get the valve stem replaced, 3 bucks and 15 bucks labor later i recieved back an over inflated tire. went home and put the tire back on. the next mornin it was flat again. i took the tire back to pep boys and told them the valve stem wasn't seated right or i had a slow leak in the tire and if they could check it. they said sure 10 mins later i got back a still flat tire that still had dirt on it, never even got inflated or put in the tank they said i needed a new tire about 90 bucks plus labor. so i took the tire to walmart the guy there, his real name was guy....go figure. inflated it and dunked it in the tank about 5 times and had 2 other technicians come look at it, then gave me my tire back and said they couldn't find anythin wrong with it no bubbles in the tank or nothin. he said he wiggled the valve stem and it might not have been seated right and he didn't charge me a dime for it and told me to come back anytime if it went flat within the next few days and he's check it again.

forget pep boys i'm goin to o'reily from now on for partsgoin to some local mechanics who are true mopar guys