My iCloud account says that it is due to expire

Where did you see this? Emails or text messages saying this sort of thing are scams, trying to get you to give away your personal details or charge you money fraudulently. Never respond in any way to this sort of thing. Your iCloud account will continue as long as you make the monthly payments (assuming you've bought extra storage - if you haven't it will never expire).

You can report fraudulent emails by forwarding them as an email attachment to reportphishing@apple.com