I think PM should, not exact, but a rough estimate, give a timeframe when porting either mobile, landline or VOIP like Fongo, so PPL at least know, if not precisely, but rough estimate of port completion at least so that they know when to at least expect when service is functioning 100%.
Plus, also give ample notice during porting that UNLESS their bills with their current carrier is up to date, if in arrears portings might not be processed.
This way, PPL have some aple knowledge on porting process, time and what happens when bills with current carrier is in arrears that their porting to PM may not be processed