Vodacom unable to perform minor account changes?

I am sitting with a friend in the UK, who issued an instruction to Vodacom to downgrade her contract to a PAYG. She left SA while still in contract, and did not have the opportunity to activate SMS roaming. We have called Vodacom, who refuse to enable SMS roaming on her PAYG number, insisting that she is in South Africa to do so. This is ridiculous, right? Just flick the switch?