From the Promoters:

It is with great disappointment that we confirm that this years’ Groundswell Festival has been cancelled due to exceptional unforeseen circumstances.
VERY IMPORTANT: All ticket sales are not held by Allez – oop. The ticket sales are held by the bank, and will be refunded in full.
Allez-oop Promotions

More Information on their site: http://www.groundswell-festival.com/news/detail.aspx?ParentPageID=15&PageID=17&ArticleID=46