Vodacom harasses me after proof of cancellation was given to their debt collectors. POPI Act doesnt apply to them apparently

I cancelled my fibre contract as I sold my house. I*** Vodacom sent me a confirmation. They first sent VVM attorneys to harass me, as I sent them the proof of cancelation. I understood from the new owners that vodacom still left the fibre on, for months after we left. I already moved out of my house in Feb 2021. Gave them notice and received of confirmation of cancellation. I forwarded the email to vvm perhaps 5 times. Now Vodacom has sent another attorney to keep on phoning me and harass me. I have proof of cancellation. So my contract with Vodacom has expired. How can they get past POPI act by giving my nr to various debt collectors, even when proof is there that notice was given. They will not stop untill I pay them, even though I dont owe them, as they cancelled the subscription upon my notice and gave me proof of cancellation.