My husband and I ate at Whataburger I Roswell NM ...

My husband and I ate at Whataburger I Roswell NM this evening and it was not a pleasant experience. I ordered a number 1 and my husband ordered a mushroom burger and was told they don't have them anymore. He asked why it was on the menu and was told "Oh, we haven't changed it yet." I went to get our drinks and 2 of them were out and The lemonade was straight water. Finding a clean table was another problem as there weren't any! Finally as we were able to sit down and eat, I took maybe 3 bites of my burger and had something odd in my mouth. I pulled it out of my mouth and it was a large piece of plastic. At first I thought it was lettuce because of the mustard on it but it was plastic. My husband asked for the manager who came and looked at it but acted as if it was no big deal. She just looked at me and said "sorry, do you want something else"? I said I wasn't going to pay for service and food like this and she did refund our money.
It's a shame because we have eaten in this Whataburger in the past and have never had service like this nor seen it so dirty. I could understand if they were rushing but there was hardly anyone there.