My father’s debt that I CANNOT afford

I have a biological father who abandoned his family ten years ago with a huge debt. I've been working since I was 18 years old at factories. I couldn't study because I had to work to look after my mother. Now, the bank is after my mother who cannot work because my biological father applied for a credit card in the name of my mother and spent all the money. When I told about what happened to us to the ING bank and lawyer. They said that I cannot prove it because the credit card belongs to my mother. All these 8 years have passed by paying my biological father's debts left to my mother. I cannot take it anymore because I am faced with confiscation. ING bank will take all our belongings if I cannot find this amount of money. The situation is pretty urgent. I am looking forward to your help. Thank you in advance.