Very very very bad and poor customer service by Retentions Agents

My contract ends on the 11 September 2020. I called and was send from pillar to post and given different advise by different agents. Spoke to retention agent Siza on the 06/08/20 time 11:58 was told i should call on the 10/09/20 to cancel my contract will not be billed or credited with airtime. Called again as i had airtime left and i wanted to know if o cancel will my airtime expire spoke to Sipho 26/08/20 time 12:20 told me even of i cancel i will still be billed and will not get airtime, but was not sure and transfered to Customer service spoke to Luthando 26/08/20 12:36 who was very understanding and helpful tolf me i can cancel today and will not be billed or credited with airtime then transfered me to retentions again waited 30 min for someone to answer i dropped the call. Called again 4times waited +-20 min to be finally answered line was bad the guy dropped the call on me. Called Retentions spoke to Shireen 26/08/20 15:03 who told me if i cancel prematurely i will be charged a penalty fee. Told me i cannot cancel on the 10/09/20 but this i was advised by Siza on the 06/08/20. Shireen told me i must call on the 11/09/20 to cancel but sadly thats the date my invoice will be processed and i will be billed for September and wont get airtime as i will be cancelling. When i told her they are not being fair and not treating me fairly becuase if i cancel prematurely i will be penalized and if i cancel on the 11th i will be billed and not get the airtime. She was not being helpful or understanding nor did she listen to my point or place herself in my shoes. She talked over me and tried to tell me about rules that have to be followed and that i signed a contract. I told her to please see things from my point of view she told me there is nothing she can do and cant change the rules and keeps o repeating herself. How is this being fair. I need an urgent response before i take it up further.