I had some work carried out on my car a month or two ago see thread below. I had a phone call from the fiat garage who carried out the work asking if a could bring the car in again because fiat head office want to check the work was done correctly.
Im not sure if they have realised they did it wrong or if they want to follow it up out of courtesy.

Has anyone else had this after work has been carried out?

https://www.fiatforum.com/grande-punto/164848-heavy-power-steering.html

It could be that Fiat have asked them to check a part due to a possible concern with a certain part number that was replaced, alternatively it could be that if the dealer is doing lots of them they want to check a few cars to make sure the components have actually been replaced. Sometimes faults come in cycles and dealers suddenly get a run of certain parts required, if Fiat see a certain dealer suddenly fitting lots of the same components compared to other dealers its natural for them to invsteigate.