Dunkin' Donuts

I understand that different places have different practices and the drinks are not always going to be the same... But this place needs to review it practices on having designating coffee pots and tea pots and not mixing the two with the same spoons etc.
On occasion when at work we order from this particular dd, I order my usual unsweetened green ice tea with flavoring and some sweet & low. But what seems like every time I order, the tea taste like burned coffee. I do not drink coffee... I do not like the taste of it.
I constantly have to throw my drink out because of it.
I have complained to them and what seems to fall on deaf ears.