Upvote:10
I don't want to stray too close to providing legal advice on interpreting a contract, given that I'm not a lawyer and especially as I haven't seen the contract. But I'm about as certain as is possible in those circumstances that "permanent resident" is being used as a 'plain English' description of the conditions defined in the contract rather than as a reference to a specific immigration status. Requiring permanent residency status in the sense it's used in your link would make the overwhelming majority of UK residents ineligible.
All that being said, the companies really should be both able and willing to clarify exactly what their eligibility criteria are, and if you have any doubts my suggestion would be to either keep pushing them until they provide an unambiguous answer, or find a different provider. Unwillingness to answer such simple questions isn't a good omen for the experience you'll have if you ever need to make a claim.