Paying for a service I can't use

Since Telkom started roaming on Vodacom I am unable to use the 1 GB all network data and free WhatsApp data that I pay for every month.

It's been 2 months now, and my data bundle rolls over, but I cannot use it.

Does this mean that Telkom has broken contract with me? I have a phone and Sim bought from them that cannot connect to the internet.

It's like selling me a car and 6 months later the car refuses to drive on paved roads. The car dealership would be forced to take back the vehicle if that were the case.