Telkom disgraceful treatment of customer after 40 years of patronage

Disgraceful service after sending official emails from my company email address Telkom Business refused to cancel the service as instructed. Historically if a monthly payment was short paid because their monthly account wasn't received and we were thereby forced to paiy an estimate they cut off our service in an instant. After 40 years of loyal patronage we sent notice of cancellation and they have continued charging and refuse to act on official instructions in a perceived attempt to dramatically overcharge for a service that is not used. I have it on good authority that I am not the only one to be exposed to this disgraceful conduct.