In some marketplaces, paid transactions may not make sense and should be disabled. Payments can be disabled for the whole marketplace or only for certain order types.
If you want to stop using only one of two payment gateways you've connected, you can find instructions here.
How to stop using payments in your marketplace
Open your Admin panel
Go to "Listings / Order types".
Click the Edit link next to the order type that you want to disable payments from.
Uncheck the "Allow sellers to accept payments online" box.
If you want to disable paid transactions for your whole marketplace, make sure that the above options are disabled for all available order types.
What happens to order types where payments are disabled?
When payments are disabled for a specific order type, the following apply for listings of that order type:
Users won't be able to pay each other during the transaction.
Marketplace administrators will not be able to take a commission from each transaction.
Transactions will be basic conversations.
Reviewing the buyer/seller is not available.
The availability management system is not available.
Is it possible to disconnect a payment provider?
Right now, it isn't possible. If you have already connected and configured a payment provider in your marketplace, it isn't possible to disconnect it. However, you can always disable the online payment system according to the instructions above, but this won't disconnect the payment gateway.