I'm sure I didn't give Twitterfeed long enough, but that's the Internet!
I googled 'alternatives to twitterfeed' and found this helpful post.
Which led me to Google's very own feed distribution service, 'Socialize', which I'm sure does lots more, but I've just set it up to send blog posts to Twitter - so consider THIS a test post...
More about Socialize
(it worked immediately btw, so I stick with this)