URGENT! - Need help in Las Vegas

Hi all. I'm at my wits end over a payday loan that I took out several months ago. My initial loan amount was $400 with an apr of 456%. I made several payments, paying the principal and then some, then fell behind. That's when the late fees started to accumulate. They were calling me everyday, at home and at work and threatening to sue me and garnish my wages. So, I caved and signed a new contract (something called an AMO loan) at a reduced interest rate of 34.90%. The new loan amount financed was around $2400 (strictly accumulated interest and late fees from the original loan) with a 5 day grace period and $41 a day late fees.

The balance has since increased exponentially. I attempted to get established with a debt management company, and they refused to work with them. I recently called them to make a settlement offer and they would not budge. They say they are going to sue and that's the end of.

A few days ago, I received a letter on attorney's letterhead saying that they had been retained to seek legal action against me and that I have 30 days to dispute. I definitely am going to dispute and demand that they show me how they calculated the crazy amount that they say I owe.

My questions are...

Do I actually have 30 days from the date of the letter to dispute?

Is there anything that legally requires them to give me a breakdown of how they calculated my debt?

Is the only way for me to halt the collections process to file a BK?

Do I have any viable options?

I already filed a BK7 2 years ago, so, I can do a BK13, but I so don't want to do that. I just don't want them to sue and garnish my wages for double what they are saying I currently owe.

I don't know what to do. I'm at the point right now of just wanting to quit my job (a job I love) and leave the state. Any help would be greatly appreciated.