Fairwinds Credit Union Ridiculous fees I guess? Winter Park Florida

Today 5/7/13 I went in to finally make the switch from Bank of America to Fairwinds. I have had an account with them for about 4 months, but haven't used it other than my initial deposit. I was aware of the monthly fee if certain criteria were not met. 

The account was opened with an initial balance of $250, I used it one time to pay for gas in the amount of $45. Well today when I went in, I was informed my account was forwarded to the collections department for being $10 in the negative. I asked for information of how the balance had went so low because there was no way the fees would have caused this. 

I am clearly done with this bank. They offered no resolution to the issue, and had a very poor attitude about the whole situation. I will patiently wait for a written answer from them because the teller was no help.