New to VM transferring landline number

I recently ordered VM broadband to replace my existing NowTV broadband and landline and is due to be installed in 2 weeks. I want to make sure I keep my existing landline phone number when my phone is plugged in to the VM hub so need the existing landline number porting from NowTV to VM.

I contacted support by phone and was told this would be done when the equipment is installed but if my NowTV broadband /phone is automatically cancelled when my VM service starts I risk loosing the existing number?

Please advise if the number will definitely be ported?