If the cheque number and amount is not mentioned in the agreement signed by you, you may issue a carefully structured communication by letter under acknowledgment addressed to the appointing authority and notify that cheque was collected from you on dated............by Mr/Ms........., designation...........department.....address........ on the pretext of ................and same is not any justified reason for which you should handover an undated cheque to the company as there is no reason, cause, debt , dues on you , hence the cheque which is obtained from you on dated........is to be read as dated...................... stands cancelled by you, and company should not present this cheque to its bankers for collection.
In all probabilities company shall become vindictive, biased, and may resort to penultimate action.
It shall be appropriate to finalize next venture and appraise the next employer in writing under acknowledgement (even if by email) the facts and that your previous employer may not issue any acknowledgment/acceptance of resignation, work experience/service certificate, FNF statement, last salary slip, etc and you can provide only copy of resignation and its POD and company may allow you to join based on these only. The company can accommodate employee.
It shall be appropriate to show your agreement and all other records you have to a competent and experienced service lawyer and give inputs in person, and let your lawyer structure your representations.
It is always better to consult elders in the family, competent and experienced well wishers, lawyer/law firm before signing on the dotted line than acting in haste and repent later.