Judgement

Hello, please help me I was handed over by body lab gym until my case is in small claims court now I am under default judgment. I was told to join the gym it a free voucher I did not ever attended the gym after few months I got a call they said I owe them I was a student I told them I don't have money and why should I pay they say I must cancel when I was there to cancel they said I can't cancel I must pay first until they sent sheriffs they threaten me to pay if not I will go to jail I agreed I only paid few months n loss my job been trying to get job but no lucky cz I am backlisted and I have Accounting and finance qualifications so next week it will be 4 years full under this default judgement I wanna get out so that I will get job how can I?