car won't start after changing key tumbler. on 1996 Pontiac Grand Am

car didn't want to start, mechanic replaced fuel pump & filter, tightened the steering column and said i had a bad key tumbler. before you had to turn the key a couple times before the car would start but it would stay running until it was turned off, then it didn't want to start again. since the work was done it wont start at all because it thru a security code/alarm? Help!!

Asked by for the 1996 Pontiac Grand Am
return for them to finish the job. the need to program the key to cyl lock