client resigns due to medical reasons, QVC refuses

Client has 15 points bought years ago. In November 2014 client contacted QVC to resign due to medical incapacity. Until now QVC refuses to accept resignation even though medical certificate sent through. QVC now wanting income and expenditure from client, even bribing with a free holiday. How must a person go on holiday if he physically can't walk or drive far, or swim? Client being told to pay membership fee even though client resigned. QVC not willing to accept resignation and forcing contractual adherence even though client cannot due to impossibility. Client turns 80 in October 2015.