PTP no refund policy

I recently downloaded the PTP CT demonstration software which enabled me to input a 2008 CT tax return.

I phoned the company and ordered the CT software.  I paid £120 by credit card.

I was sent the information to enable the software and found I could not enter a 2008 tax return because I had been "sold" the 2009 package (although I wasn't asked which package I wanted and didn't know of the distinction).  On phoning PTP I was told I would need to buy the 2008 package if I wanted to file 2008 returns. 

It seems they have a no refund policy even when they have mis-sold a product.

I will certainly never use PTP/Iris but how do I get my £120 back?

Disgruntled and unhappy PTP purchaser