MTN did not cancel my contract, now am I showing in arrears on Credit Bureau

I contacted MTN Fri, May 13 at 2:53 PM via email asking that they cancel my contract when it ends 16/07/2022 . Ref : #*** May 24 at 8:28 AM, I followed up again , no assistance.

I contacted them on many occasions and have many reference numbers. Reference Number: *** [#***].

They deducted from my account even after contract end date and I disputed those debits. When I check my credit record I see that MTN has me as in arrears and that has dropped my score and I am planning on buying a house next year.