I can see two account number on the Fido acount.
however, billing address of two accounts are different. One is old, and one is present address.
I tried to change several time, but I can't. When I changed the address, it seemed like changed. some time later, the address change was going back as old one. That means no change happened.
could anybody help me about this?
The address change on Fido.ca should definitely be working and it should update the address for each account.
We'll have to take a look at things together to see what exactly is going on and we can also update the address for you.
I'm sending you a PM to get this done, see you there!