I was at the taco bell in kings mill and the service was horrible and the workers were very sassy and rude and the sanitary conditions were horrible and a employee sneezed on my burrito and put it on a dirty surfaces

Honestly this Taco Bell makes too much money from the large theme park nearby for management to come down on them. They are also aware of this and have had deplorable service for years. I have lived in the area for a decade now and try not to go to this store for the poor quality of the food, numerous missing but paid for items, and service quality worse than their food. I had a similar experience where I did make a complaint and never even heard back from them. There is another store on Fields Ertel, not sure it is any better but if I need Taco Bell I wait to be out of the area, or just get chipotle which is right next door.

I didn't and how do u file a complaint

Hope you didn't accept the burrito. U can call the corporate office or find them online and file a report. I certainly would. That's rediculous!! Did you tell the manager on duty at the time?