Regarding OP's complaint about the tea, I think s/he is basically SOL on getting a decent cup of tea in an airplane, especially a USA carrier because:

A) the vast majority of American food & beverage providers do not know how to prepare decent tea. (This includes most ground based restaurants.); and

B) it is very difficult to brew (black) tea properly while in flight because at altitude, water boils at a temperature considerably less than the sea level 212F/100C that is best for black tea.

I have had some decent black (but not great) tea on non-USA airlines; I don't know how they do it, unless it is brewed on the ground and stored.

Suggest OP try green tea while in flight.

None of this is an excuse for poor service or attitude, however, even in Y.