Misrepresentation by Sales Consultant

I called Telkom on the 31st of July to increase my ADSL line speed, and was told I was unable to do so due an upgrade not being available in my area. I then opted to take an LTE with Telkom during the same call. When I asked the consultant on the phone if I should cancel my current ADSL service now, he said that I should wait for the new device to arrive and then cancel the ADSL service. Not once did he advise me that it would take 30 days from the date that I make the call to cancel, this order number was THD***6, please request the recording and you will hear what he advised me.

So on the 14th of August the LTE device arrived, so I called Telkom to cancel my service, and automated message then told me to login and cancel my services via the portal, which I did, I received a sms with the reference number ***4.

I called today, the 19th of August at 09:03 to find out why my ADSL line has not been cancelled as yet, and was informed that I have a mandatory 30 days cancellation period, from the 14th of August 2019.

Why did the consultant advise me to not cancel my ADSL service immediately, I would have been 19days into my 30 days cancellation period. I understand that I have a 30 days notice period, but I expect it to be backdated to the 31st of August, when I was ill advised by the consultant to not cancel my services.