I cant claim ESA BECAUSE I HAVENT PAID ENOUGH NATIONAL INSURANCE?

I am unable to work at present due to a bad back, i have tried to claim ESA but cant as i have not paid enough national ins because i have been on maternity leave and i am not untitled to the income related as my partner works, how is it fair i can not claim because i was on mat leave, can I just pay what i need to to national insurance so i can claim esa ?