To the person who had written me a pm but must have meant it for someone else since they were addressing someone else:

I responded and clarified all of your concerns as much as I could.  However, very sorry, your inbox was full and to your misfortune, your concerns remain unanswered since you didn't get my response to your pm. 

Politely suggest you not write a pm if you don't allow the recipient to respond by having a full inbox:  might just inadvertently give the erroneous impression you have bad manners.  I'll have to do a test next time before I bother to take the time to respond.

There is a feature to ban people if you do not want them to send you pm's; no need to have a full inbox.  It's very easy to delete pm's from your inbox.  Strange software where people can hang on to your pm's indefinitely.