fnb harasses me over unwanted account upgrade for cheque account

Being harassed by fnb over a cheque account upgrade that i constantly deny, keep saying that I do NOT want. Keep complaining about on their complaints page, and here. And fnb refuses to stop harassing me, and trying to force me to take that account upgrade.

Today again, I had a call from someone claiming to be with fnb, asking whether or not i was afraid to upgrade the cheque account cause i was afraid i couldnt afford the fees, or some **** like that. How much more clear do I need to be that I DO NOT WANT TO UPGRADE