Different prices for same deals

Telkom has a new deal for R750 for 10mb lte line that is capped at 250 gig, I am a existing customer with the same package but I must pay R900 and my line is capped at 150 gig when I asked why I must pay more I wast informed it is only for new customers and my package cannot be changed, I must cancel my account and apply for a new contract.