autopay machines-a bane or a boon?

they have been around for quite some time but to date, i still find them, well most of them a bane. most of the time they refuse to accept the notes, often times they are out of order and sometimes they are located at certain exits or floors only. try the ones at The Curve. yes, the parking is cheap but try leaving The Curve at night. you'll find most, if not all autopay machines are out of order that you have to pay upon exit (what's the purpose of having autopay machines then?). that's when the queue is the longest because everybody leave at the same time. buzz the intercom like mad and no one will answer.
at other places like KLCC, if you pay the parking, say RM5.50 with a RM10 note, you'll get a handful of coins in change. another thing that bugs me is that in some malls, the machines are located at certain exits or floors only. why can't they place the machines at every freaking exit on every freaking floor? you have to pay at one place and then collect your car at another. it is a nuisance. to me at least.