In the context of this particular cock-up, can you say that you're in 242B? It's not like there's anyone else using B at that address...

I've run into something like this: the common assumption is that the letter has been omitted. If they had been 242B, there would be less jumping to conclusions about where was A.

I've also lived at fractional addresses, 801 1/2 for example. I ended up being billed for my garbage and the garbage of the people who lived at 801. Same kind of stupidity.