if i want to with draw or make some changes in my application

Hello everyone,

Please tell me if it is possible if i want to change something in my application form which is under process now.Actually i have written the wrong NOC number in my application.So what exactly i should do now?Will the visa officer will change it by himself or its not a big issue if i have all proves of job experience and education? I already sent them an email and a mail by post and fax but dint hear anything from them yet. so i feel like i need to with draw first and submit my application again and if i do this. is there any rule or regulation for a person who with draw and cant apply again for certain period?. please reply me only if you have exact information.I have submitted my application in Canadian high commission Islamabad Pakistan.Please if you have can provide me any link or website in which this issue is discussed just let me know. I will be thankful to that person.

Thank u