Alright, it sounds like its in the works. Do you know where he sent it?
If it was sent back to G&G in Taiwan, it might take a while. If it was just sent to C.A.S. hopefully you should have a replacement soon.
C.A.S has a 1-877 number on their website, you could try calling them and asking how long warranties usually take
Sorry we can't help you more, airsoft warranties are a rare thing, especially in Canada.