That's very helpful MerchantVenturer: thanks ever so much.
To help others, EasyJet do make it difficult to get a refund and keep encouraging the benefits of accepting a voucher instead. You can't get on to the refund application form unless you say your flight is in the next 14 days, otherwise the option doesn't exist. (My flight is more than 14 days hence so they are encouraging me to re-book before the 14 days for free.) It's also worth noting that EasyJet are craftily transferring passengers to other flights within less than 5 hours of the original flight time, so their logic is that your original flight wasn't cancelled but simply the time changed. Of course, a different flight number tells you that in reality the flight has been cancelled!
The next challenge is to see if a refund application will be accepted when EasyJet will say the flight hasn't been cancelled (because they changed the booking)!!