chances are, those sales reps are contractors and probably dont have alot of real world knowledge how the system works.
shaw does not, and cannot use telus wiring on the street.
telus dial tone starts on the streets, feeds into the home.
shaw dial tone starts in the house (digital phone terminal) and back feeds to the rest of the house wiring, and then telus gets disconnected at the telus cse outside, preventing dial tone back to telus.
in the early stages with shaws phone service, there were issues with equipment etc. just like when telus first started phone service (or previous company) they would of had issues as well.
its the nature of the beast, just like how telus is having alot of issues with there tv service. they will get it figured out sooner or later, but without issues, nothing will get fixed!