Cancel Telkom Account but systems offline

I went to Cresta Telkom today to cancel my wifi contract and they were offline. The agent said that I can cancel my contract online which I tried but failed. Even now I am unable to cancel my contract and I dont want to pay for it for another month, taken that its the end of the month. This letter serves as proof that I tried to cancel my contract for *** and number: *** on 31 August 2020.