accidentally increase parallels hard disk size

Hi All - I've accidentally increased the hard disk size of my parallels virtual hard disk that had a Windows XP guest OS. Basically, it was setup for 8 gigs and then I increased the size without reading the fine print that all of the data would be deleted from the guest OS. Obviously it's my fault but the print is small and there was no confirmation "are you sure" or anything like that.

The problem is, my accounting software was on there and obviously as an idiotic move I was backing up the data to the virtual machine and not to the host machine (I'm not extremely computer savvy but can get around for the most part). So, I've overwritten the data because of the increased disk size and I am just wondering if there's anyway to get that back.

I've done a thorough scan with Disk Rescue II and it found some files that were deleted but not the old hard disk image I need.

So I am just wondering if anyone has had this issue and if there is a resolution to it (I'm praying I don't have to re-do 3 years of accounting).

Please let me know and any help is GREATLY appreciated.

Thank you !