Product: Vehicle loan or lease

First I am a XXXX XXXX XXXX XXXX XXXX and mainly my monthly income is {$1700.00} from SS. 
I tried to buy 2024 XXXX XXXX. 

The Co is XXXX XXXX XXXX XXXX HIGHWAY XXXX XXXX, XXXX XXXX They told me interest rate will be 16 % but on paper it was 18 % and they charged {$3400.00} with name of SERVICE CONTRACT and I asked what that is, they never explained what that is and never explained what service they did for me or the car so big to charge that much. instead they laughed and XXXX guy said its PAPER WORKING like work with computer, so I asked XXXX that you charge {$3400.00} for XXXX minutes paper working with computer.???? 

The monthly payment came out as {$650.00} and as I said I am a XXXX XXXX XXXX and live basically with Social Security income. They never told me how much monthly payment will be before I sign and never even told me what interest rate will be ( I finally asked what is interest rate I will get to XXXX girl not the dealer or financial manag because they keep saying they dont know ).. 

I REFUSE to sign XXXX paper that say the total amount of financed amount is {$28000.00} and then I found there was charge I NEVER heard and it showed SERVICE CONTRACT and the amount was {$3400.00} and I was so confused what tthat iwas at the time. 
i also REFUSED sigh on ANOTHER XXXX MORE paper that showed monthly payment will be {$650.00} but they they keep saying I signed CONTRACT and told me I have no choice but I have to buy because I signed contract, so the total financed amount was TOO HIGH and refused to sign of the monthly payment too because it was TOO HIGH too but they keep saying I signed CONTRACT,, Is that make sense to you?? 

Couple days later I tried VOLUNTARY REPROSSESSION so I brought 2024 Versa back to shop, they didnt like that and called police. 
After some argument I left car there and came home by TAXI and that was around XXXX AM then around XXXX PM I found my old Versa was gone from parking lot of my Apartment unit. 

I though THIEF took my car and called POLICE but later I found out XXXX DEALER took my old Versa because that car originally decided using for XXXX IN and my old Versa created credit {$500.00} that as trade in ( blue book say {$1300.00} for trade in ) and they brought 2024 XXXX VERSA that I left at their shop to XXXX XXXX of my unit of Apartment and it seems like they brought my new Versa by using TOWing truck. 

Thank for understanding for my not so good XXXX writing, to do writing here itself required a lot of courage for me. 
What should I do? 
i felt they really treated me badly, I have read many horror story about the old senior citizen go through auto repair shop but. 

Who ever read this writing, can you give me personalized advice? 
XXXX thing is clear that I CANT make {$650.00} monthly payment. 
Its REALLY REALLY new to me that find out car dealership try to sell car this HARD manner with almost threading way, I have been in this country for 47 years but never knew the car dealer shop people have this kind of attitude about sale, almost shocking! 

Thank youfor understanding my not so good XXXX writing, writing here itself require a lot of course from me. 

Thank you, XXXX I know I was cheated badly. 
Sir, like I said I am XXXX XXXX XXXX Korean - XXXX, what should I do??