Is it possible that SARS can tax my salary without filling any form?

Your employer has a duty to take of the tax owed on your salary an pay it over to SARS on a monthly basis. Is that what happened?

It takes me for how long to submit my return to SARS how can I submit it without any tax number or something to report with ?

Ask your employer for your tax number, if he has not registered you then if you follow this link you can see how to register for a tax number.

SARS Tax Number