Cheque fraud

dear sir , i had given a blank securtiy cheque to company on 20.12.2015 to a mutinational company.while agreement. but in last month dispute arised with them . so i done stop payment of cheque and informed them also through legal notice not to use my cheque on 22.8.2016 last week . on 22.8.2016 MD of the company having talk with me for fnf purpose payment plan as the amount is disputed i cant agree so they used my blank cheque and filled date and amount and cheque bounced today .. when i enquired in bank found date 21.8.2016 witten on it by company . how it can be used by them when there official talking to me on mail for fnf purpose on 22.8.2016 and 23.8.2016 .. is this sufficient to prove blank security cheque given