Earning R1339.56 and pay tax of R685 every week

I'm earning R1339. 56 per week so that they deduct 685 every week - is that normal?

Please make use of our SARS income tax calculator to work out how much tax you should be paying. However based on your earnings they should not be deducting any tax at all.

Thanks for the response - it's helpful. I will the follow up on that.
So who shall I contact about that is it SARS or my HR

You should contact your HR and find out from them how they worked this out.