Purchased Plot with registered agreement from person who has POA

Dear Sir/Madam, I had purchased plot with registered agreement from one person who has POA and he has attached that with agreement. This property is near to Rajangaon and under Talegaon damdhare, District- Pune. He had accepted all cheque payments for this transaction. He had promised us that our names will be on 7/12 in 3 months, but its almost 2 yrs past our names are not added in 7/12. Now this person is not picking up our phone calls and we feel like cheated. In legal perpective, what should be our first step? Thanks You, Your's Faithfully, Jitendra Atale Mobile: 904 999 5747