Don't give up hope yet, if they give you any uphill start muttering things like Sale of Goods Act etc and if that doesn't work just let them know that you only regard this as the start of the entertainment phase, and there is a long way to go yet before you are finished with them.
Don't let them think you are just another pushover!
Subtle questions like, can you speak to the manager, or if it was a national company, 'may I please have the CEO's secretary's email address', may work wonders.
Better yet, go down to the public library and look the company up in 'Who Owns Who' and 'Compass' and get the names you need from there.
Now, there are lots of ways to get at the top bloke, and it often seems like that's the only way forward, but it's far better to send a polite letter for the attention of his secretary, it's their job to stop disgruntled customers wasting their guvnor's time and you would be helping them do their job, so rather than dropping them in the mire help them out and reap the rewards.
The technique is called 'Turboing' I think and theres lots on the internet about it too!
Hope this helps and good luck.
If all else fails and you paid on a credit card phone 'em up and see if they'll reverse the charges. That'll get some movement on the issue!