My question involves criminal law for the state of: North Carolina

I need help and I don't know what to do. I worked for this credit card company for 10 years so you would think I would've known better. Here is the situation. I was laid off in Feb 2010 and unemployed for a period of time. I grew up in Charlotte, NC and my 88 year old grandmother lives there and told me to come back and get a job in Charlotte since it is a bigger city. When I came down, she offered me her credit card to use as long as I paid the bill. The card had a zero balance so I knew whatever balance ended up on it, would be mine. I lived with my grandmother the whole time I used it and paid it religously every month (and still do). I admittedly let the balance get up high ($10,000) and I knew I shouldn't have. I moved out of my grandmothers home in Jan. and shortly after I started receiving awful phone calls from her and my sister. They are saying they are sending me to jail and making demands that are not reasonable. Every day it is something new and some harrassing message or phone call. I can't keep going through this. I just want it over. I have no problem paying my debt but they are demanding money out of me that I don't have and threatening me with jail every day. I am a single mom of a teenage boy and I don't need my son seeing me taken to jail. I also work and go to school and don't want my whole life ruined over this by having charges on me.

Help... What can I do or what should I do?

Thank you!