It should be possible for you to get a change of phone number. One of the VM forum team will be able to advise further. They normally reply within a few days but can take up to a week to respond.
Be aware when you change numbers that the 'new' number actually comes from a long-standing pool of numbers owned by VM. The 'new' number you get may possibly come with its own set of problems depending on who has owned it in the past and how long it has been out of use in the pool for before being put back into service.
I'm getting a large number of unwanted calls and as I work nights I'm constantly getting woken up. I don't want to have to keep turning the phone off and on. I just want to change my number.
Everyone is receiving these scam calls, irrespective of their phone number or their service provider. The calls are automated and just work their way through blocks of numbers at a time on a particular area code.
Consider getting a caller blocker device or phone. Check out the post below from earlier this week on someone with the same problem who has just fitted one.
These are happening a lot at the moment, If you feel that changing your landline number would prevent this I am more than happy to change that for you, however there is still the possibility that this could still happen.