Happy Little Quilt Shop review: This store took out parts of my bernina 770qe and replaced them with wrong parts

I bought a new 770QE with embroidery module in 2018 from Stitchin' at the Barn, now known as Happy Little Quilt Shop in Imlay City. This shop no longer sells Berninas, so for regular maintenance I took it to a shop in Flint in May 2022. While there, the manager found that my machine had internal parts missing and they had been replaced with parts from various Bernina models. The only place I had taken the 770 was to Sitchin' at the Barn (AKA Happy Little Quilt Shop.) The Flint store manager found out in October or November 2022 that the 770 was altered and told me about it in November this year. It is no longer a true 770, and Bernina USA reported that it will be difficult and expensive to get it back to proper 770QE specifications. Any repairs or maintenance by Bernina or a shop will be unusually expensive, and for their part, difficult to do. I had trusted the shop people, and never compared the serial number so I do not know when it was altered. I did know that the machine cover had been changed to a 750 (I think) cover, and the manager said he could not find a proper 770 cover each time I asked for it. Bernina USA commented that even changing the cover to the wrong cover damages the machine. I spent $3899.71 on the 770 + turned in a 580E which was in good working order. Cost to repair the 770 will be at least $1000 per Bernina USA. I have reported this also to the Michigan Attorney General Consumer Protections Division.