1 month turnaround time for repairs

In December 2020, my car went in for repairs and it took 1 month to fix bcz they had changed the system and there were issues with getting parts. There was poor feedback to a point that my husband had to physical go there in order to get some explanation.

For my sins I needed repairs again. The car was towed on the 13th of April to date it has not comeback. The response we get is that it has not been even stripped to identify all problems the parts arrived on the 25th I still don't have the car it's the second of May. Going to another month without a car when my business is dependent on it. What bothers me is the take it or leave it attitude.

How am I suppose to consider a merc when their customer service way below standard of late? It is not acceptable.