Tracking is indeed via intmail.183.com.cn, whose website says it was delivered (on a day when I was NOT home), after an unnsuccessful delivery attempt the day before (when Iwas home all day).

I have a 13 char (alphanumeric) ref # from China Post which has the correct format (9 digits topped & tailed with 2 letters, last two being CN for china), but which it isn't recognisd by Royal mail's tracking website ("sorry, There is no data currently available for this tracking reference. Please try again later.").

I didn't think to try the royal mail website until long after the China post tracker claimed it had been delivered, so I don't know whether that error message is because the item is now flagged as delivwered, or whether it is actually a bogus ref #.

Anyway, like I say I've given up chasing - buying goods from China via a 3rd party website was a bit of an experiment for me, I figured if I lost $13 it wouldn't break me. I've now got a UK supplied battery + desktop charger and I'm going to chalk up the chinese scud to experience :-) Thanks for your attempts to help though, appreciated.