Onairtv ******ion

I wrote them an email on the 1st of January to advise Onairtv of my intention to cancell my fibre service agreement at the end of January 2023.I sent this notice to their following ***,fibre.co.za@onairtv,*** When i called to enquire,I am told that I need to send to a specific email address yet the company use all these emails.The contention is that I now have to pay for one more month because of this.