What the recipient do under reverse charge machanism

in a case where the Reverse charge machanism apply,

1. If the provider of services lavied ST in his bill even if 100% liability  is of reciepient  ?

2. Provider lavied 100% of ST even if the 25% & 75% bearing criteria is there.?

whether the recipient paid ST amount to the vendor what he lavied or create a liability of service tax as per machanism?

or need to take fresh bill from vendor?