Has anybody explained why we haven't received a refund?

Assuming that the rules are similiar to what happens here once practise has started and you have practised then no refund is possible.

I will ask and find out for definate give me a couple of hours

I'm sure you're right, Cargo, and there is a reply to a similar question, regarding the curtailment of the Jurby meeting yesterday. You can find Keith McKay's explanation there.
http://www.andreas-racing.iofm.net/
The thread is cancelled races.

Well our club cancelled a whole day last season and everybody got a refund (credit note)

If the whole day was canceled then there would be no reason not to have a refund/credit note.

I'm waiting for a reply from the MGP office on this me thinks they are off for a couple of days or very busy getting regs and entry forms ready.

Yes, I think that's right. If you start, then the insurance is in place, has to be paid for, and no refunds are possible. If, however, the whole day is called off, and noone turns a wheel, the insurance was not needed and you can have your dosh back.
I should think the MGP office is a hive of activity... everywhere here is suddenly "race-ready"! I'm waiting to see the first bale of the season... like the first cuckoo....

Just got word from the MGP office and my thoughts were correct.

Once practise has started you money is spent

Sorry

On a happy note for all you MGP riders keep a close watch on the post something may arrive very soon

Oh, goodie... is that a cuckoo I hear???