I called Fido cusotmer service to port my number for fido after getting the fido Sim.
but they completely messed up and i lossed my existing number. tried calling from last 2 hours but they keep me bouncing from one department to another but no real solution.
really fursteded 
Hello Sandeshmhatre,
Welcome to the community!
Sorry to hear you're having issues with porting your phone number. While I'm unaware of the exact details, I don't think Fido would have lost your existing phone number.
Had you cancelled your services from your previous provider prior to requesting the port-in? You should note that your phone number and account needs to be active for the porting process (see here). As far as I am aware, if the porting process was unsuccessful, your number would revert back to your previous provider. Unfortunately, if you had cancelled your services prior to requesting the number ported-in, Fido would not be able to get that phone number.
Alternatively, is it possible the number port is only delayed? Depending on the circumstances, it can take up to a week for a port-in to complete.
If you would like further assistance, you would need to contact customer service. In addition, they can also be contacted via Live Chat, Facebook, or Twitter. Those methods can be accessed via the contact page posted above.
Hope this helps 😀
Cheers
