Vodacom milks existing clients

My vodacom. Contract is due for an upgrade however, the system does Not allow me to downscale, only to increase my package? How is this fair for an ongoing client for years? It is cheaper to take a new contract than to upgrade. Really vodacom, is this the way you treat your existing clients? Watch out vodacom clients, do no allow them to bully you, it is your choice weather you want to increase or downscale!