Glynner my sister used them last year and like a previous poster said they were disorganized to say the least, I really thought she was being scammed, but they did come thru with the tickets in the end and hopefully they will for you too. I recall it was very close to the wire tho, someone met her on the night with the tickets.
As regards where you stand or how to approach it if it doesn't come thru, I'm afraid I'd tell you the same thing I told her, it's tout territory basically and I wouldn't fancy your chances, particularly as you sent them a cheque so no chargeback possible