Dissatisfaction

My dad bought a Telkom phone on contract in 2018 August started paying in September the contract seeded on the 30th September so we requested a cancelation letter but no one responded to us, on the 25th of October Telkom debited my dad's account with R150 which was not in agreement with him, in November again they debited him. Last week we called to request a cancelation letter again but now they claim we owe them R440. We request immediate refund and a cancelation letter. If not attended I will take this matter even further. My dad's name is Jabulane Nkosi Contact:***