Delay and no resposne from university on pay protection and joing date.

I have received an offer of appointment at Level 11 pay scale from an autonomous university under GNCTD. I immediately accepted the offer and conveyed my acceptance to the university also I have resigned from my current position at CPSU(Maharatana). Later after one month I received a letter for a medical test, which I attend and got my medical done. I was in a notice period of 3 months, meanwhile, I raise the query of pay protection as per the extant DoPT orders with the university. I did not get a satisfactory reply on the pay-protection subject. Even on physically meeting with the establishment division of the university they said, it will be sent for approval once you join the university. So they postponed everything to my joining, they could not even assure me an in-principal approval of pay protection. Seeing all this ambiguity I decided to withdraw my resignation from my current PSU employer, and I withdrew the resignation. I mailed to the university that I need clarification on the pay protection before joining along with other 2-3 points as per the DoPT guidelines. I did not get any reply for 2 months, then I decided to meet the appointing authority at the university for a matter of pay protection and other issues. The Registrar has invited me to meet physically to discuss my concerns. The Registrar resolved my queries except for the pay protection subject, for which he called someone from the finance/establishment division and gave them my papers for getting clarification on pay protection and assured me of a written reply within a few days. But more than 6 months have gone I haven't received any reply from the university. I have been giving them incessant reminders over email quoting the reference of my meeting with Registrar. After seeing no reply to my all emails I gave representation in hard copy and got a receipt from the University office as well. Its been one month since I have given the representation in hard copies and asked for assurance or otherwise a written reply from the university so that I can resign from my current organization and serve the notice period. It's been a year since the original date of the offer of appointment. 1) I want to know if, can they cancel my offer of an appointment without addressing my concern or giving me a chance. 2) I could not join because they have not till date addressed my query/concern. Will i be at fault for not joining? 3) If they cancel by assigning the reason for the long delay in joining, can I proceed legally. 4) how should i proceed from here, I am interested in joining if they give me the pay-protection.