I came to the USA in 2007 and became a Permanent Resident through marriage to my husband who is a US born Citizen. Our Marriage is legitimate. I have not visited back to my country ever since I came here as I always wanted to first get my parents for a vacation to the USA . Recently I sponsored my mother, father and young brother to visit me and my husband in the USA. I sent all required sponsor documents of me and my husband. My parents also prepared all necessary documents to show the ties to return back.
Unfortunately all three of their visa got rejected under the 214(b) statement. The counselor has said since I went to USA and never returned back they cannot trust my parents either. Neither my parents nor my brother has any intentions to settle here in USA. They are well settled in my country.
Now I want to re-apply for their visa again. But I am afraid their visa will be rejected again. Please give me advice on things I should know before I re-applying and how I could convenience the consulate officers to grant my parents Visa.
Is it OK to re-apply all three of them together again? I want them to visit me as a family all three together and have a family reunion. Please give me advice on the best way to get my parents visa approved

Which consulate or embassy did they apply at?