RPM Auto Sales, Inc. attempted to sell me a junk titled car from out of state and now wants to charge fees to pay via credit or debit card six months into the financing contract Lansing Michigan

I originally agreed to finance a 2004 Chevrolet Monte Carlo with RPM Auto Sales in Lansing Michigan aproximately 6 months ago. After a week of driving it while they processed the title, they called me to inform me that I needed to return the car because it turns out the car was previously titled to a salvage yard in Indiana, and Michigan won't allow salvaged vehicles to be licensed for use on public roadways. As an alternative, they sold me a 2008 Buick Lucerne for the same price. Now that I've made 5 payments in person (it's a 50 mile round trip from my house to the dealer's office and back) 2 to 3 days prior to the due date each time, they want to tack on a $2.00 "convenience fee" to all credit card and debit card transactions. This forces me to withdraw cash at an ATM which charges a transaction fee of $3.00 to make a cash withdrawal to avoid the dealer's convenience fee which was not disclosed when the sales contract was signed. Based on the unlawful sale of the Chevrolet and the nondisclosure at time of sale of "convenience fees" that are anything but convenient, I feel that I'm entitled to keep the car and void the contract, releasing me from all future payments.