Virgin Media’s mobile service was launched in 1999 as a Mobile Virtual Network Operator. It currently uses the EE network. It was bought by Liberty Global in 2013. They offer both a pay as you go and contract mobile service. It has had a 4G service since 2016.
The 02 number represents local numbers for regions of the UK. They cost between 3p and 55p per minute approximately. If you are calling from abroad it may be much higher. Please note that you may get free calls to a few numbers as part of your specific package. You can buy 02 numbers here.
If you have any problems with your phone calls or the charges associated with various calls please ask for advice from Ofcom. Alternatively you can ask Virgin Mobile for further details.