Arrogant service provider!

My problem started when I wanted to terminate the contract due to myself relocating from my property. I called metrofibre to terminate the contract when I decided to rent out the unit, since the tenant also needed WiFi service, I informed metrofibre and was advised that they will change debit order to the new occupant instead of cancelling the service completely. That was done, few months later after the tenant had exited the unit due to property being sold, I received an outstanding balance statement of over 4 months that the tenant did not pay!!! I asked them to remove the debt from my profile but I was told that was not their problem, since I was the original owner of the account I should settle the debts, it’s not their problem!

Despite my efforts of engagement with them that I can’t be held responsible since it was a mutual agreement that the tenant will take over the service ( hence we amended banking details) Instead the account has been handed over to debt collectors who harass me on daily basis!😡😡😡