Continuation of Benefits While on Leave

I have a Federally regulated employee who left at the end of June 2021 for a six week leave to have a surgery.  He has not returned and we are still paying his benefits.  He initially received STD through Service Canada then was denied LTD through our plan since his over 65.  We have no medical information provided, he does not stay in contact and merely says that he may or may not return, just that he doesn’t know yet. What recourse do we have to either collect the EE share of the benefit cost or have his benefits suspended without actually terminating him?