Question about I-130 petition

I am us citizen and I applied I-130 petition for my parents and I was assuming that my mom and dad both will get visa on one petition. But now national visa center saying that only my dad will get visa. To get visa for my mom I need to file another petition for my mom I want to know the petition I already filed and now it is in Nation visa center my mom can get visa. any thing can be done or any lawyer can give help that both my mom and dad get visa. or I must have to file another petition for my mom.