Sprint charged me over $600.00 with out my permission.?

i recently paid my cell phone bill with my debit card for $200.00, i have 3 phone lines, one for work, personal and one for my wife. a few days after paying my bill, I receive a call from my bank saying that i have an overdraft of 200 dollars, they bank employee went over my charges with me online and it showed that sprint charged be 200 dollars twice and the next day, they charged me 289 dollars, I called sprint and they said it was my banks fault and that i need to take it up with my bank. I called the bank back the bank put me on 3 way in the phone, the bank was on mute and was recording the conversation, after litteraly 5 hours and being transfered to 12 sprint reps, sprint finnaly admited that it was there fault and they would ONLY pay the over draft fee. As for the other money that was mistakenly taken out by them from my checking account with out my verbal permission or written permission, they would not refund it. I then was told that I could file an investigation woth Sprint corporate, but unfortunatly i would have to call back the next day, I was pissed. Today sprint calls me and apologises and offers to send me all the money back, plus deduct half of my next phone bill, and i would have to wait until 3-5 business days in order to get the check from sprint for the money they owe me. this sucks because i now have no money in the bank and i have to buy my college books by this thursday. What would you suggest????