How do I add an *additional* line correctly?

I'm trying to **add** a mobile plan for my wife to my existing Rogers account. When I go through the steps to try to purchase the new line, the rogers website makes it seems like it's going to overwrite my existing mobile line with a new number. It basically says "Line 1" and gives me a temp number, **but I already have an existing "line 1"** that I don't want to change. So I haven't actually submitted the order, but there's no other path on the website to actually "add" a new line.

We've had Rogers Home for a while, but mobile was with another provider.

I went through the steps to create my mobile account with Rogers today, and was able to transfer my number relatively smoothly (some hiccups, but it worked in the end).

When I went through the BYOD deal on Rogers website, I swear there was some text that said you can add more lines after, but as described above it seems like it's going to overwrite my existing line.

What's the correct way to get a new number added?

Thanks!