Need suggesion

firends

my registration nuber is SRO0257721. i completed cpt in dec. 2008, since then i did nt register for exams ( ipcc)( means didnt  make application for exams) but now iam trying to apply for nov attampt  thorugu online , in online application form when i enterd my registration number it is showing that invalid registration number, why? what i have to do now ? i calld to chennai , but i ddnt get proper respond from their. pls give me suggestion.