Please see :-
The important thing to note is that you should type the name of the new provider in the box and then press the TAB key. This will bring up a New Rehab Provider screen for you to enter the details. This way you will only link the new provider to this case and not change the details of the original provider.
The incorrect way of doing this is shown
The details of the rehab provider are changed by clicking the "View Details" icon next to the name and then overwriting the details for original provider with those of new provider You have not created a new database record just updated the details for the existing provider. All cases linked to the original provider will have their rehab provider changed.