Even though I have deleted alerts, the recipients still receive an alert

I tried removing the alerts from the UI, but the recipients still received them.
I deleted alerts from the DB, but we still receive them.

DELETE FROM pulse WHERE id = <alert_id>;
DELETE FROM pulse_card WHERE pulse_id = <alert_id>;
DELETE FROM pulse_channel WHERE pulse_id = <alert_id>;

The queries given above are the ones I used to delete the alerts from backend.

I used the queries to delete them because even though the alerts were marked as archived, we were still receiving the alerts.