Disable all other payment gateways if not wallet rechargeable cart.

pay_only_with_wallet.php

if(!function_exists('woocommerce_available_payment_gateways_callback')){
    function woocommerce_available_payment_gateways_callback($_available_gateways){
        if(!is_admin() && !is_wallet_rechargeable_cart()){
            foreach ($_available_gateways as $id => $gateway){
                if('wallet' != $id){
                    unset($_available_gateways[$id]);
                }
            }
        }
        return $_available_gateways;
    }
}
add_filter('woocommerce_available_payment_gateways', 'woocommerce_available_payment_gateways_callback');