Well, that can be pretty frustrating. Especially if you suddenly can't draw any money and noone can really tell you why.
1-Do maintenance starting at 8PM on a Saturday night instead of a remote time when it's unlikely many people would try to access their account.
2-Do it over a three day weekend meaning anyone who does accidentally lock out their account can't get it fixed until Tuesday the next week, instead of immediately.
Oh, and as I stated elsewhere, banks usually impose daily limits for ATM withdrawals. It's actually designed to protect you, mostly.
That doesn't mean the bank has to do the above listed things.
Are you
certain that it was closed for maintenance? I think you mentioned that you made multiple withdrawals on the same day before your attempt that locked you out. If so, then this is pretty normal.
Most banks impose limits on the number of withdrawals you can make per day. The reasons for this are two-fold: to prevent possible identity thieves from going on sprees once they find that they can access the account a first time, and also to prevent possible 'runs on the bank' (unlikely but true). The former is there to protect you, so I really don't get why you felt the need to hurl abuse at them for it. I'd love to know what you'd have said to them if somebody had got hold of your card and started making unlimited fraudulent ATM withdrawals, thus emptying your account.
