ICANN - Internet Corporation for Assigned Names and Numbers - has introduced the Expired Registration Recovery Policy (ERRP).
According to the ERRP, all registrars are obliged to implement several procedures, such as the domain name system suspension (DNS suspension) at least eight days before the domain cancellation date. After the cancellation of the domain there is a period called redemption period, during which the owner of the domain can recover it at an higher price.
Contact your internet service provider to renew the domain in order to avoid cancellation and to bring back immediately online your website.