Car issues after taking it to them

I brought my car for a service and it was ABSOLUTELY fine, it even had less kms than it was being serviced for. The moment it came back, it started making funny sounds and 7 days later, it shut down completely. It started acting up exactly on what they had quoted maintenance on. It just doesn’t make sense to me that a car that didn’t have ANY issues would just go from that to a complete shut down after being touched by them.