This sounds so much like an episode from Seinfeld, and a quite uniquely American way of doing things.
You asked that your account be closed, not because you want it closed, but because you want someone to second-guess that you're closing it because something's wrong with the way you're being treated.
People open and close accounts every day for innumerable reasons.
If I clossed all my accounts with everyone who didn't answer emails, I'd have no accounts left.
The problems start when we beat about the bush. Tell them you're not happy and why up front.