Why would my engine start misfiring after having Air Conditioner Orings put in?

What is your question?

Had no problems at all with my 2002 GMC envoy except no air conditioning because of a leak at the orings so I Had the air conditioner orings put in and when they crank it up as soon as they were done with installing the new orings and gaskets it is missing and misfiring, won't turn over unless your holding the gas, won't idle at all, spitting and sputtering when it is running and you can't drive it anywhere cause it dies as soon as u try to put it in drive. What's wrong?

What makes this problem better or worse?

Cranking it

How long has your 2002 GMC Envoy had this problem?

Since yesterday 6/26/2019