Changing the number, where your existing one is on a scammers' list and is being specifically targeted, may be the solution here but may only offer a short term fix to scam calls in general.
Any 'new' number you are allocated will not actually be new but will be recycled from a pool of existing VM numbers. The 'new' number may come with its own set of historical problems (such as being a former business number etc.). Examples of this are documented on the forum. In addition, any new number will still eventually be subject to scam calls from auto-dialling software.
Out of interest, which call blockers have you tried? Who set up the device(s) for your parents?