Pending registry from more than two and half months

I have purchased a flat in Uttam Nagar in a new constructed building. On the date of reg we went through all processes in side registrar office like photo-sessions, finger prints etc. Finally we received a slip ( Cash receipt ). Then our builder handed over that slip to the bank lawyer (from where I borrowed loan). Bank lawyer then handed over the checks to builder, and we were told that registry is completed and bank person will show that slip here in registrar office tomorrow or day after tomorrow and then he will get and submit registry to bank, and later we will get its copy either from document writer or from bank. After around 4 - 5 days when I contacted to my builder then they told that registrar of registrar office is changed, and your registry is pending. After that whenever I called to either builder or bank lawyer I am always getting the same answer that since registrar is changed so it is still pending. Sub Registrar office is in Janakpuri west. Please guide me.