Maintenance for the week of March 3:
• PC/Mac: No maintenance – March 3
• ESO Store and Account System for maintenance – March 4, 6:00AM EST (11:00 UTC) - 4:00PM EST (21:00 UTC)
• NA megaservers for maintenance – March 5, 4:00AM EST (9:00 UTC) - 11:00AM EST (16:00 UTC)
• EU megaservers for maintenance – March 5, 9:00 UTC (4:00AM EST) - 16:00 UTC (11:00AM EST)
From memory if you want to update or change your card, you have to cancel the membership and then renew it. You don't lose out over it, it's just a cumbersome way of having to deal with a simple change. I think that's what I had to do when my card expired and was replaced with the same number but a later expiry date.