is vodacom gone crazy or is it my phone?

hi there

3 months ago i was given a huawei P8 as a present.

Since I started using my new phone, my cellphone bill has doubled, but my usage has not changed at all.

I buy bundles and vodacom is constantly telling me that my bundles were expired and they have billed me data charges.

So i have an enormous bill... like seriously huge... almost a third of my salary.

I call vodacom and they say i dont have a choice i need to accept the billing.

can anyone help?