Telkom Integrity

I went the first view days in August to cancel my Telkom. I had to go into the store and the consultant said I will not be paying for Augusts as I cancel the contract in the beginning of the month and will switch of the rooter on that day. So did not have any WiFi. Now there is letters send that I owe Telkom for that month? What happened to integrity. Still I did not hear from them and did send in a dispute. But I get a letter in the post that I need to pay....