add_filter('woocommerce_available_payment_gateways', 'show_bacs_if_coupon_is_used', 99, 1);
function show_bacs_if_coupon_is_used( $available_gateways ) {

        $current_user = wp_get_current_user();

        if ( isset($available_gateways['bacs']) && (current_user_can('customer'))) {
             unset($available_gateways['bacs']);
             } else if ( isset($available_gateways['bacs']) && !is_user_logged_in())  {
             unset($available_gateways['bacs']);
         }
         return $available_gateways;
}

add_filter('woocommerce_available_payment_gateways', 'show_bacs_for_specific_applied_coupon', 99, 1);
function show_bacs_for_specific_applied_coupon( $available_gateways ) {
    $coupon_code = 'FOOD';

    if ( isset($available_gateways['bacs']) && ! ( is_user_logged_in() &&
    in_array( strtolower($coupon_code), WC()->cart->get_applied_coupons() ) ) ) {
        unset($available_gateways['bacs']);
    }
    return $available_gateways;
}

add_filter('woocommerce_available_payment_gateways','show_cheque_for_specific_applied_coupon', 99, 1);
function show_cheque_for_specific_applied_coupon( $available_gateways ) {
    $coupon_code = 'GRP-';
    if (in_array(strtolower($coupon_code), WC()->cart->get_applied_coupons() )) {
        unset($available_gateways['paypal']);
        unset($available_gateways['satispay']);
        unset($available_gateways['stripe']);
    }
  return $available_gateways;
}