I've also used sendit.com and had no problems with either communication or delivery. They're based in NI if I recall.
One issue I did have with them - on first purchase, they "test" the credit card by charging then crediting £1....of course it didn't convert exactly on my CC bill so I was charged something 6 or 7 cent! I did send an email to sendit.com to query the matter, and got a very nice reply promising me 50p credit....never got it though (wasn't about to raise hell over 7c, life's too short!!).