MTN is a lair and *******!!!

Good day, I would like to tell MTN that they are the worst service Providers ever, in November last year I got a call from a MTN agent, who told me he can help me with new bundles on my 5 contracts I have with them, its 3 sim cards only and then 2 phone with Sims I usually contract for 24 months. When he phone he told me I he can help me with contracts on the sim cards to make my payments each month lesser than I currently pay each month, my number,I should have upgraded last year in Nov, but I told them I will wait as they did not have a new Samsung note as yet. And told me all Samsung notes has been disconnected, as I did not want another make phone I said I will wait. Last moth I decided oky I need a new phone so I will go see what they have. Got there they told me I can only upgrade next year 2024 August as the agent that phoned me upgraded my Sims to all sims only, i can upgrade now to a new phone if i pay R700 now, how can they tell me i am paying for sim cards only but i can upgrade now if i pay R700, which by the way was deducted from my bank when we left the MTN store, on query they told me it is a debit order and can't be reversed? ***! Now this is unacceptable as this was not discussed with me by the agent that it will only be for the 5 sims. Now I sit with an old phone that is freezing for nothing, and I can only upgrade next year, and I pay currently more each month than I did before the agent phoned me. Please assist with this matter on what I can do. Kind regards A very ****ed soon to be ex MTN customer ***