Can DingPOS track card and mobile payment fees?

Yes. In Settings → Payment Methods, tap a payment method (or add a new one) and fill in Processing fee: a percentage, a fixed amount per transaction, or both. From then on, every payment collected through that method records a fee estimated at the rate in effect at that moment.

On Stats, the Payment Methods card adds a line “Fee · Net” under each method that has a fee, and the foot of the card shows the estimated fees and estimated net received for the whole period.

• Enter the rate your provider actually deducts, tax included — for 3% plus 5% tax, enter 3.15%. Leave both fields empty for no fee.
• A rate change only applies to later payments; fees already recorded stay as they were.
• “Percentage fee returned on refunds” is on by default, for providers that give their fee back when you refund. It governs returns and refunded pre-order deposits: with it on, the percentage comes back; the fixed fee never does. A void or an undone settlement ignores the switch and takes back the whole fee it recorded, fixed fee included. Either way, the customer gets back the same amount.
• Payments collected before the method had a rate carry no fee: Stats marks them “N missing a rate” and shows the net as “—”.