There may not be an easy way to do it. Samsung devices are not carrier locked until a SIM card is inserted. You can try calling Telus and explaining what happened but it's hard to say what can be done. Normally carriers won't unlock a device unless certain criteria are met, like no device balance. I'm not sure if Fido could do anything with it or not since the phone wasn't supplied by them, but as a last resort you could contact them also. Samsung may also have a way to reset the phone back to the state it left the factory in but you'd have to contact them to see.
Don't call fido. They can't do anything for a Telus phone. Call Telus and explain the extraordinary circumstances. They may be able or willing to make an exception. Referring you to Samsung requires a lot of time and effort on your end for a simple mistake.