Scheduling and Authentication Failures

Client has numerous complex recurring schedules - XI 3.1 - not sure which service pack.

Individual who created schedules retired and user was removed

Jobs scheduled for end of week were still in place after user was deleted, but failed upon running and then disappeared.

Also, no failure notification was sent.

At end of MONTH, there are a bunch more jobs that will attempt to run against this userid

1. How can they modify month-end jobs so they don't fail?

2. How can they get back the week-end jobs that already failed and disappeared?

3. Why didn't they receive failure notification?

I asked them to submit as support case, but also thought I would post here.