Urgent! Dealing with GC Services/Citi by tomorrow

I recently settled my Chase account thru GC Services. Now, they are after me on my Citi card, on which I owe $24K (was 20K before extra fees). I first defaulted last January so it's been 9 months. I also owe another creditor $12K and another about $1,500, in addition to a sizeable car loan, student loans and two mortgages. GC Services tells me the Citi account is in "pre-legal" status. First question: are they just saying this to put pressure on me? As I told them, if I get sued, my only option is bankruptcy in which they will get nothing. How is that a good option for them?

Second, they're telling me I should agree to settle at 50% of the balance - their offer - and I have 12 months to pay it off locked in at 0% interest. I don't feel comfortable agreeing to that because it might be literally impossible for me to pay it off, especially if I lose my job or get a pay cut come January (definitely a possibility). They say they can't go lower than the 50% offer unless I can come to the table with a lump sum. Has anyone been in this situation? Should I agree to it despite the risks, or stop talking to them for now and try to save up a larger lump sum? They say if I agree to the $12K now, I can always call them at any time during the year with a lump payment and try to resolve the whole thing for less.

I have to call them back tomorrow.

Very confused, in dire need of advice SOON -- please help!!