I overstayed my Chinese visa in 2010

Hello,
Plz advise me, i went to China on 2010 and leave PRC in 2011(overstayed for a year +) The agent that handle my documents told me that i can apply for a new entry permit when i arrived Nigeria after 3-6 months . But i have tired all my possible best for years to get Chinese entry permit but no way. Finally i got an invitation letter from my supplier in PRC and went to PRC embassy in Nigeria to apply a new entry permit with my importation documents. After the interview which is 2014, they issued me an entry permit and later cancelled the entry permit at PRC embassy. I want to know if it is still possible for me to apply again?