Hi Phil & Julia
I've been having the same problem (see my post LGW to CFU on 20th December) I rang XL Airways who told me that 'Pure Flights' was the operator of the charter for these flights so I rang them and a was told that these tickets were sent to the agents last Monday. She also offered to e-mail my tickets direct to me and I received them just a few minutes later.
Strange thing is that about an hour later I got an e-mail from 'Mastersun' (don't know where they fit into the equation) with the exact tickets I wanted but for someone else. I've still not heard anything from the agent but for me, it doesn't matter any more, I've got mine!!
Pure Flights: http://www.pureflights.com
E-mail: fly(replace with an 'at')pureflights.com
Phone: 0870 767 7774