I thought that this was an issue specific to my account or perhaps the coin, but it seems someone else is having the same problem:
https://bitcointalksearch.org/topic/btercom-scam-the-theft-proof-367372
I'm posting here as it will probably be more visible, and I'm not accusing them of scamming, so... is anyone else experiencing this issue too?
I've had to resort to splitting my deposits to minimise loss, because I know that sooner or later one is going to go missing. Sure enough, for the amount I split into two deposits about an hour ago, only one deposit was credited; the other showed briefly as "Processing" then just dropped off as if it had never been seen.
Support has not replied to my multiple emails about this. I'm assuming they've been deluged with requests from n00bs like every other exchange recently. I would, however, like this problem fixed.