The employer took my signature on a loan I never took to pay visa expenses upon resignation

Can an employer get a signature on a loan paper for giving them a job & after resigning asks them for visa money or else they will file a case against the loan amount?

Please guide me, in such a case, what should that employee do because they hold the passport?

They cancel the visa & do not give the canceled paper so the employee should change the status to avoid a fine. They just keep on blackmailing me to get the visa money in terms of the loan paper.

Is there any possibility to show the bank statement that we never received such an amount?

Or the employer never has the cheque receiving, but just the loan request paper?

Can you please guide me?