Yes, a month is more than ample really. Thinking further, I probably should've just done the refund on 26 Mar when they contacted me (I'd messaged at the time of sale/post saying the PO advised at least 1-2 weeks, which seemed a long time etc etc and the buuer msg'd back agreeing to let me know when it arrived).

I've recently heard of mail from rural Vic - rural Nsw taking 3 weeks which I found pretty amazing, and I once got a refund myself from a seller in Qld when an item didn't arrive in 3 weeks.... then a week later it showed up! So more messing around to fix that with the seller, although it worked out fine in the end.

It was great of the buyer to continue using msgs rather than opening a case, not all buyers do. Perhaps a good reason to send buyers a short msg when posting, which I sometimes do and sometimes don't. Might make a point of it in future.