Towing Issues: Towing Extortion, small claims court, filing a lien

Question
My car and a trailer was towed Friday night from a store parking lot.  The tow company said they would not release my car and trailer until Monday because they were closed.  They later said I would have 30 minutes Saturday to pick it up and pay, but I had to pay 4 days storage and the fee in CASH.  He also said that if I waited until Monday they would be filing a lien against my car because it was over 3 days and that would increase the cost by $120.  I had to pay $830 cash on Saturday.  This is extortion, but he had my car and I was trapped.  What can I do?

Answer
very important information is missing here.   Each City, and State have different regulations and they regulate pricing, release policies and such.

Now this does sound bad, but most tow companies are closed on weekends. The office that is.
But there are generally ways to get vehicles on weekends and after hours.  After hour release fees, or gate fees are usually charged.

Depending on where this happened the local police might be of some help or various state agencies like the PUC, or other regulatory agency.

And you are always able to go though small claims court and see if you can convince a judge that you were wronged.