Is there any way to get a VF Prepay number re-enabled after it has been 'retired'/unused for more than a year?

The situation:

1) Son-in-Law used to live in NZ and had a NZ phone/SIM on VF Prepaid

2) He has been living in Australia for the last 3 years.

3) While out of Australia visiting his homeland (not NZ), his phone/SIM (and wallet, passport and other valuables) were stolen.

4) He was unable to return to Australia for several months due to Covid lockdowns.

5)  The original number has not been used since then (according to VF).

6) Covid and other family matters have also prevented him returning to NZ to sort this out.

7) Recently he has begun to rediscover several accounts he had  forgotten to maintain for which access is dependent on authentication requests sent to his old VF NZ number, which of course he cannot receive and use to respond to the validation request.

He would like to regain access to these accounts, and needs the original phone number working to do so.

It may be far too long after the fact (and let's not go down that 'why has he left it so long?' rabbit hole, as there is no way to change the past anyway), but is there any way at all to restore the use of his original (02108xxxxxx) prepay number e.g. by re-livening the original number and swapping it onto a new SIM? 

Appreciation for any helpful suggestions in advance! (but I suspect I know where this will end up going. Gotta try anyway, just in case)

Thanks.

GK