Vodacom upgrades totally misleading

Upgraded with Vodacom recently with my upgrade being due. Received an sms today with my next debit order amount, being R188 more that my contract amount. Called Vodacom only to be told that this is a handset fee I have to pay for the next three months for the full 24 month duration of my old contract. Since when!!! I have been with Vodacom for 15 years + and have never ever been charged this when upgrading. Very disappointed.