I did some search in the foruns and it was never clear how to fix this so I will write this down.
I was trying to oderer a sim and I kept getting 'Zip code does not match billing address'. I read the forums and they suggested to try zip without spaces, etc etc. I tried a couple of times. Every time it failed with the same error.
I decided to check my Credit Card and I've noticed there was an entry of CAN$10.50 by public mobile and a lot of pings. Probably one for each try.
So if you are getting that message, do not try again, check your bank statement to make sure it did not go through.
Hope it helps.
@rasalom, I just tried the ordering system and the postal code does indeed work with a space in the middle. What I also found neat was that I just entered the postal code and the system pull my address and provided me with a list of house numbers to select. So, chances of mis typing the address is pretty much eliminated.
Anyway, if you have been charged and was not able to put through the order, please contact the moderator team and they will help to sort things out. The moderator team can be reached via private message using this link. Refer to the following knowledge base link for information on contacting the moderator team.