pepper cash didnt want to do a 3 way conference call with my bank so my wife told them we were not interested in a loan and the next day they deposited the money. Internet

my wife and I were researching payday loan companies and came across pepper cash. we filled out all the preliminary information via the internet .  when all the information was given you had to type your name in the electronic signature area which i am fully aware is giving legal authorization to proceed further with the loan. after we typed in our name they said thank you for your inquiry and a company representative will call you the following business day . a pepper cash called my wifes phone the next day and left a message to call them back.   my wife called them later in the day and were discussing the loan and they wanted to do a 3 way conference call with our bank.  my wife did not feel comfortable doing this so she said she was not interested in the loan and told them no thank you.  well the next day low and behold the money was in our account. we just figured well we will just pay it back and be done with it .  we knew going in that payday loans have a very high interest rate but at the time with our situation we kept the loan.  well it turns out that weve now paid over $700 in payments  and out of that money only $50 has been applied towards the principal.   i guess what we are more upset about is that my wife told them no initially over the phone and they still gave us the loan.  i contacted pepper cash this evening and told them everything that i have entered here and they said that if your wife said no over the phone about the 3way call we probably just had you fax us your bank statements. well no person in there right mind would do that .   they did confirm that they received no bank statements or other financial information from us but that there representative made a mistake and gave us the loan anyway.  i then asked for a copy of our notes and they said it was in the notes where my wife declined the 3way call and they admitted that they probably made a mistake giving us the loan anyway.  im just wondering if i have any options of not making anymore payments. we are thinking of putting a stop payment on this company against our acccount but im pretty sure they will try to sue us for the remaining money owed and the interest will keep piling up.  they said if we pay them $250 on monday they will close the account .   do we have any legal ground to stand on with this as far as not paying them anymore money.  i dont think we would win if we tried to sue them.   if anybody has had this happen to them and were successful in doing the stop payment route id sure would like to hear from them .   thank you