Hi SitFidoSit & welcome to the Community.
The Samsung Galaxy S5 has been discontinued. That said, it will no longer become available.
You can check out our other awesome phones here though.
That's too bad. I really wanted to upgrade my Galaxy S3 to the S5. Fido still has other older, discontinued phones like the Galaxy S4 available so I would hope the S5 would be made available to Fido users.
It's been discontinued, so Fido can't order more. Most likely, the stock they had has been all sold, while they haven't been able to sell the S4 they still have - people are more likely to want an S5 than an S4.
Hence, the S4 is still available, while the S5 isn't. It's not a matter of Fido not wanting to offer the S5, it's that they cannot get any.