Thanks WorldofNeil for the reply, i thought my plan of paying for each would be the only way to do it, which is acceptable, I'd been hoping for another way but no worries.

You can only change a name once per day (I don't know whether this is 24 hour period or calendar day).
I'd assume this was 24hrs from the time of purchase.

I am uncertain though if there is a delay on the old name being released so you can use it again.
with my idea confirmed That's what I truly want to know, if there's a Delay of say, 2 hours, 24 hours, a week. I know some game tend to keep your old name reserved in a kind of "backup pool" for quite some time. yet I can't find this info here.

What I know so far to recap.
Will need to pay 3 times for name change
24 hrs between each purchase. (Possibly from time of purchase)
Thank you for your time, if anyone could answer the other question it would be much appreciated.
How long until character A's name is back in the pool for selection.