Product: Vehicle loan or lease

I signed a purchase agreement contract for VIN # on XX/XX/XXXX on XX/XX/XXXX. I have been the victim of harassment, predatory lending practices, and unfair and deceptive trade practices at the hands of Instacredit Automart. An auto sales dealership in the state Illinois. I am requesting that this contract and all amendments thereafter be thrown out or null with all payments you have received for the said contract be returned to me in full. I am arguing several reasons that I feel this is a practical request. First, I was misinformed about the value and history of the vehicle. I was not informed that the vehicle was previous used as a rental for a rental business. Had this been disclosed, as required by law, I would not have agreed to the purchase of the vehicle. I have only recently become aware that my rights as consumer, per the Consumer Financial Protection Bureau Mandated by the FTC, have been violated. 
The first complaint I have actually occurred on XX/XX/XXXX, but was only recently made evident during a phone call conversation I had with XXXX during XX/XX/XXXX. I asked her if I could have my sentimental belongings back that were inside the vehicle when it was previously missing from my apartment complex parking lot unbeknownst to me, XXXX stated that my belongings were destroyed after only three weeks of being in the companys possession. This is a complete violation of Illinois state consumer financial protection law. Most of the items were sentimental and are therefore irreplaceable in monetary value. This is disheartening and has caused a great deal of grief. 
My second complaint has to do with the companys debt collection practices. As I feel that these too have violated my rights. They were both harassing and deflating to my character per several witness accounts. When a friend of mine, who luckily happens to be a licensed financial adviser, decided to help me get the loan made current, she was shocked because the collections representative XXXX made derogatory statements that were defalcating to my character! 
As upset as I was still seeking to bring my loan current. I was denied any correspondence from company that they claimed was sent to me and I had never received. I was then transferred to the supervisor XXXX of their legal department. I calmly relayed my concerns of the full obligation not being satisfied upon return or repossession of the vehicle, as the value of the vehicle only covers approximately 10 % of the actual {$10000.00} purchase price. This is without the preposterous 25 % interest rate that I am currently being charged. I was only XXXX years old when I signed the contract last year and admit I had no idea what the given interest rates were had it been through an unaffiliated, more prominent lending source : such as a bank or a credit union. I was not provided with any 3rd party interest rates and was made to believe that XXXX XXXX XXXX, the companys subsidiary, was my only option for financing. This being said, and the fact only their company benefited from this, there is no denying that I have been taken advantage of and this company has committed unfair and deceptive trade practices as well as unfair and deceptive lending practices. Had I been presented with interest rate options that should have been legally made available to me perhaps this would have been a purchase that I could have afforded and not defaulted on. After informing XXXX of the XXXX XXXX XXXX quote of ~ {$1000.00} on the vehicle, in which he replied, I could sell this car for much more than the actual value to another buyer, I am certain repossession is not an uncommon practice for your company. However, this is an unfair trade practice and harmful to any consumer. There were also witnesses to this conversation that are willing to testify.