Worked for 3 days in a company - hey have not returned my original certificates

Hi, I have been selected for a company 1 month ago. I have given my original documents. After joining I have been working for three days only. After that some reason I cannot continue. I have given my resignation. But till now they have not returned my certificate .there is no bond or any things but they not returning my certificate. Now, what to do?

If there is any notice period you have accepted then you have to serve that period before being relieved. An organisation is not a revolving door place, you enter through one and exit through the next. The organisation's rules and regulations have to be duly followed.
You have to pursue with them to return your certificates, since already much time has elapsed after you left them, you need to issue a notice asking for immediate return of documents. I hope they haven't paid you, then they cannot insist on notice period. But if they have paid you, then there is no escape from serving the notice period.

The organizations which are keeping the original certificates of the employees under their custody are not professional organizations. There must be some wrong intention for those organizations.

It is a caution to employees that under any circumstances original certificates should not be left under the custody of the employers. Employers may ask for those certificates only to cross-check with the photocopy. The owner of the original certificates is the concerned employee not the employer.