I rang Leicester a couple of months ago, when everyone started saying the tickets were being recieved for other dates. A lady at their box office checked my order details, explained that there must have been some sort of admin error with my particular order and that I should have had them already, apologised that I hadn't had them and posted them straight away. I got them a few days later. I would strongly advise you call the box office, as clearly there is some wider issue regards sending the tickets, than just mine being delayed.
You couldn't buy me with a million babe