Say what happened plainly
State that the renewal payment did not go through, without blame.
Make the fix one step
Link straight to the page where they can update the card.
Say what happens next
Tell them how long access continues and when it will pause if nothing changes.
Follow up once or twice
Send a short second note a few days later, then a final one before access ends.
Offer help
Give a way to reply if there is a different problem, such as a changed bank.
Welcome them back
When it is fixed, confirm access and thank them.