How ignorant. And rude.
I eventually got out of my seat and tracked her down across the room asking her sweetly, "May I have a refill?" With great reluctance I was ultimately granted a third (gasp!) refill, but she made it known that, "Refills are extra!" and promptly disappeared into the depths of the kitchen
Well fiddle-dee-dee.
I finished my meal and as I made my way to the cashier, Miss-Tea's-Too-Valuable-To-Squander-On-Paying-Customers, noticing, no doubt, from her righteous lair that I'd neglected to leave a tip on the table came charging to the pay station with a condecending, You-May-Have-Forgotten-A-Little-Sonmething,-Pal look about her.
I ignored her and paid the bill sans what now seemed like such an oh so precious tip. To this day, when I dine out my planned tip is 20%. The help can expect me to begin mentally paring that generous amount for things like inattentiveness, a bothched order, etc. And not refilling my tea glass when empty.
As to sweet vs. unsweet: here in central OK, most tea is served unsweet except for some catfish and BBQ joints. However, as you move south and east in the state, the likelihood of being offered sweet tea increases. So, I wouldn't say that Oklahoma is lost to the "true South" just yet.