late settlement with commsec- best strategy?

Hi Guys,
Long story short, I've purchased an not insignificant amount of shares (about 150k). The money I was expecting to pay for these with has not come through, and won't be there by t + 3. Ordinarily there wouldn't be a problem, I would just sell the shares and take care of it, but the company is in a trading halt which means I could be up to a week late by the time I can execute a sell order.

My questions:

1. Is it best to call them and bring the situation to their attention, or would it be better to try and "fly under the radar" and hope for the best for the week?

2. What is the likeliehood of them selling the shares me??? And logistically can they do this since they are in the same situation as me, the shares can't be sold because of the halt!

I'm more worried they'll execute a trade on open and then pocket any gains!

Any thoughts and opinions would be appreciated. I hope this is the right forum to post this question in. Cheers.