Salary on Hold

Dear Sir, I resigned from the company dated 28th Feb 2019 through a written intimation by mail and the company accepted the same. The Company's policy is to clear the Full & Final Settlement after 45 days of resignation. So, after 60days, I asked the HR about the same. They directed me to the Accounts Dept. The Accounts department told me that there is market outstanding against my name, hence my F&F is on hold. Sir, I would like to mention here 1. All billing to parties were done in writing & with written approval from the director of the company. 2. The Management without informing me appointed a person in my position. 3. so I resigned myself when i came to know about it. 4. In such a case, when I have already resigned, is it not the duty of the current team to followup with these parties for payment & close these cases. 5. I have also suggest that, if required I am ready to cooperate with the current team and help in recovering the dues. 6. My point is - I was only an employee of the company & all billings were done with the prior approval of the director. So How Can i be responsible to recover the dues. 7. Besides me there are other members of the team like accounts dept, ASM, etc. who are part of the whole process. Therefore, what remedy I have to recover my F&F settlement in this case ? Please revert at the earliest. regards razi ahmed