The settlement for all net sales is done the next day, so for example all sales from today less any refunds or reversals from today will be settled tomorrow. So, the net sales for the 31st of January will be settled on the 1st of February, the net sales for the 1st of February will be settled on the 2nd of February etc. The amount that is settled is the balance of the total incoming amounts (e.g. debits) less the outgoing amounts (e.g. refunds)
The settlement is done automatically by Nedbank into your business bank account, so you do not need to do anything from your side. The funds will then reflect immediately if you bank with Nedbank, or after 1-2 business days for other banks, due to inter-bank delays.
On your bank statement, it will show the line item "Nedlink DP" plus your merchant number.