The cost of fund withdrawal via Zamtel is 3% with SuperForex.
The cost will be deducted from the withdrawal amount by SuperForex to process the withdrawal via Zamtel.
You can see the full list of the available withdrawal method for your account, and the related cost for the withdrawal in the client cabinet.
If the bank, card company, or payment service provider you are using charges fees for transactions, then you may also need to cover the fees on your side.
Normally, SuperForex deducts/covers the fees of fund withdrawal beforehand, so the fee charged by your payment service provider should be zero or minimal.