Stupidity for Dummies?

T-Mobile has done several things that well...suck. We set up a payment plan for a large bill (since they overcharged us by $80) and my fiancee specifically said "I will make payments at the local store". Just before oure rent is due, we get a notice stating that $277.55 (the remainder of the bill) has been taken out of our account!! We called customer service and they said they couldn't do anything since we set it up!! Well, that, unfortunately was our rent check. Next, they shut off a phone too soon, which means we got charged (on two consecutive bills) an extra $200!! Plus, the bill before that, our bill was only $50. That does great for budgeting because our bill this last time around (with no extras and one phone coming off) was $126. What? I'm about fed up with this. My fiancee had a phone stolen by an ex, that he had on his plan...and instead of shutting off the phone (which still incurred regular service fees until its shutoff date in december) they re-upped his contract on the phone!! Can anyone say "Retention"?

Has anyone else had problems like this? What did/would you do?