I have seen some discussion elsewhere as to whether they come under regulation 41.

This answers the question.


12. Where a trader offers a technical support line, this need not come under
regulation 41, provided it is a discrete service, and not one on which the caller
is also expected to call to discuss problems with a purchase already made.
Provided the trader makes it clear that it is a separate service for which a
separate fee (paid for through the enhanced cost of the call) is payable and
not one for post purchase problems, regulation 41 will not apply. Horoscope
and weather lines are similarly excluded. Regulation 41 applies where a
phone line is offered which allows a customer to contact the trader about a
problem which may have arisen with a product already purchased or to
exercise cancellation rights.
 
13. If, however, a consumer having contacted a ‘paid through a telephone bill’
service, is unhappy and wishes to raise an issue (for instance the recording
was muffled and they could not hear it properly) then, if the provider offers a
phone line for such complaints, that phone line should comply with regulation 41.

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/310044/bis-13-1368-consumer-contracts-information-cancellation-and-additional-payments-regulations-guidance.pdf#page=23&zoom=auto,0,580

There is merit in this statement but I would suggest that the majority of enquirers would neither terminate the call or even complain because it is too much hassle.