Inability to reach Telkom to cancel data bundle

I have spent hours trying to reach Telkom in the past month to reactivate my DSL router after lightning damage. I have now given up and have decided to transfer my line and data to another ISP. In order to do this, I still need to contact Telkom to cancel my existing data bundle.I have been unable to get through. I just want to end this relationship!! Shall I just stop paying and wait for the debt collectors to phone me so I can have a conversation about this? Or can Telkom kindly contact me? Also no response on my Web query...