Telkom bills full rental for suspended lines

Telkom is billing me for a suspended line! I tried to cancel my Telkom line repeatedly for 3 months during lockdown. Online option was faulty and I could never get through on the phone and due to lockdown I could not go in store. Eventually Telkom suspended the line Nov last year. End Jan 2021 I receive an update to the suspended line's invoice with a full rental amount for Jan. On querying this with their attorneys FOURIE SIKWEYIYA INC of www.dcfourie.co.za I was told that suspneded lines continue to get charged full rental. How can you charge for something that is not in use? I am not allowed to cancel the line until the bill is paid for in full. Remember that I tried to cancel the line for 3 months, to no avail, hence an arrears has built up and I am paying this off every month but in the meantime the bill is increasing. Is this a money making scheme? I am frustrated and shocked at this inethical behaviour.