Over draft frustrations

I am fed up and don't know which way to turn. I was retrenched for the first time in 2015 and since then have been having problems with my fnb cheque account overdraft. It was handed over to their lawyers. I lost everything because of not being able to find work and ended up living by my sister. I made payments as I could and the amount wasn't too bad. I found work in Cape Town but was retrenched again last September. I have an arrange ment to pay R150 per month and even through doing odd jobs I paid R200. I have been able to find work and the lick down has made it impossible. Their attorney has contacted me and has demanded payment or they will take further legal action. The overdraft is now more than double the original outstanding amount due to interest and bank charges. I will never be able to back the moneyI am living with my mom and her pension is barely keeping food on the table. What must I do? My savings account is also in the negative because of bank charges. Where do they think I must pull the money out of?