Firestone complaint: Car damaged/wrecked

I took my vehicle to be serviced at the Madison Avenue location in Memphis Tennessee they had my vehicle for four days as they told me they had to order parts wait for things to come in I thought it was a simple easy one day maybe overnight repair but it ended up being a four day ordeal Causing me to get a rental car and then when I went to pick it up that Thursday when they told me it would be ready it wasn’t I had to wait for sensors to be ordered etc. my main complaint is during the time that my vehicle was in the possession of fire stone Something happened to it somebody either drove it off the property maybe to test the AC ran into some thing straight on because the damage to the vehicle is at eight front direct impact and I know that when I drop the vehicle off to be serviced there was no front and Damage nor had it been wrecked so I would like answers to what happened to my vehicle while it was in the possession of fire stone and I would also like my vehicle to be fixed back to the hundred percent it was when I dropped it off minus the repairs that had nothing to do with the cosmetic damage that has been done to the vehicle . Please advise!!