International roaming for prepaid customers not available - does this affect my bbm ?

[Padded Mouse]

Can anybody explain to me why Cell C does not have international roaming for their prepaid customers ... the internet says its available, but have just spoken to a customer service person who says it is not and that if I want international roaming, I will have to take out a top up contract.

I don't want to do this as I am moving to the UK, but do want to be able to be in contact with my family whilst I am en route up until they meet me at the airport.

Does this affect my ability to use whatsapp and BBM as well as calls and sms's