@nsthankiya -- there is a similar thread in this discussion forum:
https://support.shaw.ca/t5/home-phone-discussions/one-number-i-call-rings-busy-but-when-i-use-my-cel...
Together, all the suppliers of telephone-services maintain a database of which supplier receives & delivers each call to each number. Given that "number portability" is common, one never knows which supplier "answers" a specific number. For example, 778-465-0001 may be routed to a Shaw land-line, while 778-465-0002 may be routed to a Telus mobile-phone.
So, ask Shaw to check that database, to make sure that they are the supplier of calls to your number. Also, if you have a cell-phone managed by a different supplier, ask them to check that database, from their end.
> Shaw tech support has no clue.
Sigh. That is bad training of the first level of Shaw Support employees. The principle for all "help desk" operations is to answer what can be answered, and then to "escalate" any unresolved issue to the second level of technical support. Any employee who says "I have no clue" needs more training.
Ask all your friends, with different suppliers of telephone service, to try to call you, to see if any get connected.
Do you have any local friends with a very-similar telephone-number, e.g., 778-zzz-xxxx, who also use "Shaw Phone" as their supplier, who can connect to you? Such a call will be routed entirely within Shaw's network, never "crossing-over" to Telus/Bell/Rogers network.
