SARS pay date for refund - 21 days?

Good day. For the tax year 2015 I filed my tax return at the branch then called to follow up when they paying me. I was told I need to file the outstanding 2011 and 2012 tax return. I registered for e-filing and did that on Saturday then Sunday morning I was sent a statement of account. It says "selected for audit", so I called the call centre to follow up again when I'm getting paid. They say up to 21 working days, is this right?

Yes that is correct, they need to now process these old tax returns unfortunately which can take longer than the usual waiting time you have been used to in the past.

So everything seems in order then? And what's the earliest and latest they can take to pay me?

Yes that is correct, you will receive a Letter of Completion once they have done the audits after which you will receive your payout.

But I was not selected for an audit

Apologies, I meant after they have finalised the older assessments which usually take longer than a current year's tax return.