The Delivery Address Problem

I bought tickets for the August Reading Festival in July. When the tickets had not arrived within a week, I contacted them and they replied as follow

"There are some tickets are not normally printed until a week or so before the game. Ticket Distributors do this to decrease the probability of fraud.
Therefore tickets are not usually sent out to the buyers until 3 or 5 days before the event. It is down to the individual seller to decide when they are able to send the tickets. This may be due to holidays etc."

The 3-5 days before the event is important as described below.

With the start of the festival on Fri 23rd Aug, I was informed by e-mail on 20th that the tickets had been handed over to the courier (Royal Mail).
The next day, I get another e-mail with the courier tracking reference and with a screen shot of the Royal mail tracking website which said

"We were unable to deliver item xxxxx as it was not possible to identify the delivery address. We returned the item to sender on the 21/08/13 13:44"

The tracking number was not supplied until after the attempted delivery.

That same e-mail stated that as I had provided a wrong address they were not liable to refund my money and I should claim off Royal Mail for not delivering it!

The address details entered at time of order were correct.

Royal Mail state that returned packages can take up to 5 days to be returned to the sender. Therefore, it is very unlikely that if the sender had included a return address, that the ticket would be back with him in time for the start of the festival and hence arrange other ways of collecting the ticket.
So at the time of the festival/concert the package (which probably does not contain the ticket in the first place) is in the Royal Mail system.

Therefore it is likely that;
Whatever was sent by recorded delivery was (a) not the requested ticket and (b) had an incorrect mail address so that there was no chance of the package ever being delivered.
In doing this, however, the seller can claim that he has sent it (as he has a tracking number) and it wasn't his fault that it did not get delivered.
Royal Mail are unable to confirm what address was used for delivery hence convenient for the seller