California Lending Law violations on a Vehicle Title Loan?

I took out a vehicle title loan over 2 years ago. I am in CA, and so is the finance company. At the end of 2 years, the company, without my knowledge or consent, changed the terms of the loan, reducing my minimum payment from over $300 a month to $80. They refuse to give me written documentation of the new terms aside from the monthly statements, which do not mention financing terms. They said it was "to help me out" and called it an "internal revision" and that there is no paperwork to give me. This past month they added $170 to the amount due with no mention of why or what it was. I had to call them and they said it was a repo closure fee because they canceled a repo after my payment was 6 days late. Been late before and they never charged this fee. I'm getting uncomfortable. Advice?