In debt because of we buy cars

We buy cars did me dirt as I purchase car from them it come with tracking device which they had to pay upfront payment they never did I was paying for it until I’ve realise that I’m paying double since it was financed I tried to reach out of them no1 assisted me even the sales person who helped she was no longer Answering my calls now I’m the 1 owing netsta while it’s their fault so whoever want to purchase car with them make sure u don’t sign those contracts without going thru and understanding this people are unprofessional my experience with them is bad I don’t wish it to happen to anyone