Debt-In harrasses bordering on ********ity

Debt-in is a debt collection agency for Telkom. I had an issue with my Telkom account in which Telkom charged me for an installation of a wi-fi router that never happened. I have tried repeatedly to get this issue sorted with Telkom. In the meantime Debt-in have been calling me up to 10-15 times PER DAY to recoup a relatively small amount of money. The call centres operators are *********** and rude. It's pathetic. If any company is looking for a debt collection agency, do not use Debt-In