I had something similar a while ago with Cox. I had EFT setup for quite some time. I was moving between two apartments in the same town so I gave them a call and had them transfer service from apartment A to apartment B. They told me I just needed to take my cable box and modem with me and hook them up.
Everything seemed fine initially, until I looked at my bank account the next month. Apparently they don't "move" accounts, they cancel the old account and then open a new one. When they cancelled my old account it saw that I still had my cable box and charged me >$200 for it. Because I was signed up for EFT they instantly withdrew that amount from my bank account. However, when they opened the new Cox account they credited me for the cost of the cable box on that new account. Note that they didn't REFUND the, they just counted it towards my future cable bills.
I called them up and they claimed there wasn't anything they could do to refund my money without waiting over a month. It was absolutely ridiculous, they can take money instantly yet they take forever to refund it. If I waited that long to pay what I owed they'd send me to collections.
The only financial thing that I could think of that got my more upset was when I had just opened my credit union account. I deposited a large check (~$10,000) into my checking account and they put a hold on it so they could verify it was valid. New account, large check, its understandable that they were a little suspicious and I didn't think much of it. When they hit the legal limit on how long they could hold the check they shifted the money out of my checking account into my savings account which apparently lets them reset the clock on the hold. They never asked me if that was ok and never informed me that they had done it. I'm sure they would have charged me over draft fees too if I started writing checks, expecting that the money was still in my checking account. I was absolutely pissed that they moved money between my accounts without informing me. That sort of stuff could seriously screw up somebody's finances.