In case of Transporter, If service provider book (Show in Invoice) whole liability of service tax i.e. 12.36% then recepient of Service is liable or not for service tax.
In case of liability under Reverse charge Mechanism, service recipient is required to pay Service Tax to the Department and not to the service provider. But in case service tax has already been paid which is not correct legally, it should not be paid again as it is a revenue neutral situation. However, the Department may litigate on the same.