We had tickets for comedy clubs, given as a gift. Didn't originally look at the expiry date, as we thought we could extend them. Turns out you can extend them...for a £20 fee. Given that the vouchers were worth £34, that felt like a ripoff already. So had to book asap. Then it turns out (small print!) that they expire on 1 December, making it even tighter. Found a date: 14 November, and tried to book it. Oh no, you can't book it, you have to wait until someone does it for you. Four days later we got an answer: no, can't book this, they need two weeks notice, we had given them 10 days...
Tried to get a refund: nope, but told me i can extend the voucher, for a fee.
Tried again, this time with more than two weeks' notice, gave them 2 dates, 2 venues, 30 Nov, 1 Dec...another four days went by: nope, no availability. Now too late to do anything, because we no longer have two weeks' notice.
Complete and utter rip-off. Do not use them, they're cons.
Recommendation: Stay away.