Price increased without authorization!!!

i took a fibre contract with Telkom in October 2023. i was given an amount that i would pay for the duration of the contract. but to my astonishment, Telkom has debited R620 end of April. i called in to enquire & was advised that Telkom increased their prices on the 1st April 2024. i did request a manager to call me to escalate a complaint but haven't received any calls yet. i will be sending a formal complaint via email to have this matter resolved before lodging a case with the ombudsman. Service No. B*** we take cell phone contracts for 24 or 36 months & we're required to pay the same amount for the full duration even though the phone value decreases rapidly yet Telkom has the audacity to breach the contract & increase prices whenever they feel like. this was not mentioned in the call recording & i was lead to believe there will be a fixed price! i will require the call recording for my submission to the ombudsman.