Harassment for issuing us Transfer of shares certificate.

We purchased a 1 BHK flat from a seller in a CHS Ltd that time matters was under discussion between Ex chairman with old committee to be resigned and new Chairman and committee to be form. We got a NOC from Ex-chairman when he was having authorization to sign society documents. Now also all signatures on cheque happening thru Ex chairman; New chairman and committee has taken charge but not authorized to sign on cheque yet. Our flat is registered with all stamp duty paid to government and we got bank loan on the said flat. Now we approached new Chairman and committee members to transfer flat on our name on SHARE Certificate they are not willing saying NOC issued to us from Ex Chairman is NULL and Invalid. When we asked current committee members to show us document stating resigned date of Ex-chairman. They are not able to provide us document. We checked with Ex- Chairman the date of his resigned it was 8th- March-2015 and we had NOC from Ex Chairman dated 1st March-2015. Since our flat was registered we started out some repair work in flat which we gave society committee in writing that we have started repair work on 1st-June-2015. On 27th-June-2015 new committee issued letter and send it to us in writing to stop repair work because yet your name is not transferred in Share certificate and society is not given permission to carry out repair work. Please advise us on 2 things. What action will be taken on Ex Chairman for issuing us NOC and second what we should do to get this matter completely resolve with getting our names transferred on Shares Certificate.