Unfairly treated

I have been a vodacom customer for over 10 years and recently was contacted to purchase 2 contracts which I agreed to and have received. I was advised that this would be billed with my monthly bill. To my dismay I was debited twice within a week of receiving my routers. This was not the agreement that we held. As a big corporate company I don't feel that it's fair that they feel they can take advantage and lie to clients. I feel that I have been treated unfairly as a customer.