Through Orbitz, I booked a flight with Air Berlin from Venice, via Berlin, to Santorini Greece.
Now my connecting flight leaves 30 minutes before I land in Berlin. They do not have any other flights that day.
I have tried to phone Orbitz but cannot afford to be on hold from Australia & their customer service online says I have to phone them.
I purchased a saver fare (nonrefundable), but am I entitled to a refund if they cancel my flight?

Yes. They will refund.

Do Air Berlin do connecting flights?

Most low costs will only do point to point tickets and hence will accept no responsibility (and no refunds) if for any reason you were unable to get the onward flight.

You contract is with Orbitz, not Air Berlin and as they booked you for Venice to Santorini via Berlin, it is THEIR responsibility - and their's alone - for refunding / changing your booking

Sadly, you have to deal with Orbitz. This is the risk of booking with an online agency. Until you fly the first flight the Travel Agency (Orbitz) owns the booking. So you are going to have to call.

Just thinking, could you use online chat or Skype to avoid phone charges?

Orbitz has an online chat available. Here's the link to the page - it's all the way down at the bottom.

http://faq.orbitz.com

Thankyou everyone for your help. Refund is approved.