CAN'T CLOSE ACCOUNT

Since the Body Corporate of her apartment complex refused to repair or replace the landline running to her flat last year, my mother-in-law has been trying to close her Telkom account. After submitting the second Consumer Service Cancellation Request form (definitely to the correct email address), I started phoning those pleasant and helpful people at 10210. I have been informed "Yes, I see your request, I have spoken to the relevant department, they will action it this week, here is your reference number" on at least two occasions, and still the monthly accounts roll in... Recently she received an SMS threatening legal action! VERY FRUSTRATING!! Any suggestions, please?