If a payment fails, or you cancel your subscription, your club doesn't get deleted or locked out. It goes read-only. Everything you've already recorded stays fully visible: fixtures, results, stats, your whole season's history. You simply can't record anything new, including fixtures, results or squad changes, until the payment issue is fixed or you resubscribe.
To fix a failed payment, or to resubscribe after cancelling, use the same billing portal or checkout described in Upgrading, downgrading and managing your card. Nothing about your club's data is ever affected by a lapsed payment.