Integrity Advance scammed me!

I have a loan through Intgerity Advance, are they legal in Minnesota? I saw aMoney Mutal ad on tv, and went online to find out info, and got a call from I.A. instead. They said they could borrow me $300 and it would be taken out of my checking acct. in $90 increments. They lady never said I had to call ahead 3 days to tell them to take more out that would go towards the principal too!! Instead the $90 only went to the finance charges and other fees, and the loan was "renewed". So $825 later I called to tell them they were overpaid, and they tell me I still owe $200!! It was all stated in the agrrement plan that I "signed". Yes I applied for the loan but on the phone, I was never told to sign anything, and was never e-mailed the terms, I know stupid on my part, but they said they could never had proccesed the loan without my sig. They said that after the phone call I went online and "signed" it. I never did because I never got it, only more ads from them wanting me to take out more loans. After crabbing at them for 20 mins the supervisor said she'd waive certain charges but I still owe $105!! After they've already gotten $525 over the loan from me!! Do I have pay this or can I close my account? They are going to take it out on the 24 of this month, but I cant afford to pay them anymore, I feel Ive already paid what I needed. PLease any advice would be greatly appreciated.