The customer service rep. told me that a support ticket has been opened for the issue. And it probably takes up to 7 days to have it sort it out.
I desperately need to contact my parents both are over 80s in China under the danger of flooding and 2nd wave of Covid-19.
I hope the customer service rep. can use their virgin landline to ring any Chinese number just to prove the existence of the issue, but they said they were not allowed to do so.
Virgin media is not rally helpful on this matter although I have subscribed the highest phone package with them, Anytime + International calls.
What a waste of my time and money!