Resignation accepted after 55 days after end of notice period

I have given the resignation in my company which has the condition of one month notice period. Even after the completion of the notice period, company has not replied on my resignation and now after 2 months they are mailing me that we have accepted the resignation from the date effective from which you had given the resignation. Due to their non acceptance of the resignation I was not able to join anywhere else and now the company do not want to give the salary of the delayed period so today they have mailed me that we have accepted the resignation from the back date. I just want to know whether the company has to give the salary for the 2 months which they have willfully wasted even when I was ready to complete all the documentation done for the resignation. They have first time sent the documents related to resignation 55 days later after completion of the notice period. What Should I DO? Just accept it and get whatever dues they settle or ask the company for the 2 month salary?