terrible food and rude manager

Last Saturday night my mother and I had dinner at the Red Lobster on Pleasant Hill Rd. in Duluth, GA
I have to eat gluten free and the time before when we visited this restaurant it had a "lemon, garlic, and butter sauce" to go with the Salmon.  Instead it was a cream sauce instead of just butter, lemon, and garlic.   A lot of people don't want cream sauces.
So we decided to give it other try last week and asked for the manager to explain that we just wanted the butter, garlic, and lemon sauce and the reason.  The waiter was from another country so I asked for the manager because I thought that might be the best thing to do before ordering.  The "manager" who said her name was Donnell (but later we found out it was Darnell.  She gave to our table and glared at us instead of saying hello and what can I help you with.  She was very rude.   I had a simple request and she first ignored me and acted like we had asked for the moon.   She also was foreign, but it wasn't a language problem just a bad attitude.  The sauce we did get was very bitter as it was almost all lemon and on the side instead of having a little lemon, garlic, and butter cooked on the salmon.   The salmon was tasteless.   I wasn't able to eat much because of that.   We ask the waiter, Emmanuel, for some butter to delete some of the lemon bitterness.   It was separated and look like butter on the bottom and water on the top.  The so-called manager never came back and ask how things were.   The regular manager, Jeremy, was off the has apparently been off alot as he was never there when I called.  Never want to eat there again!   With all the people out of work can't they get good help, especially managers