Angry!!!!! Why are RSVP's being lost in the mail????

So I am being super stalker and have e-mailed and facebook messaged a bunch of people who I thought didn't send in RSVP's.

So far 2 people I have asked sent in their RSVP's ages ago and we never got them!!!!

How is that effin possible?!?!?!

The RSVP envelope was professionally printed and we got sooo many back so why would some get lost?!?! One was mailed from the town over from where my parents live (who get the RSVP cards).

Tomorrow is the RSVP date so I'm just annoyed that the USPS can get their sh*t together and deliver the smallest and simplest thing!!!!!!!!!!