None responsive and just unprofessional

I’ve been getting emails and smses from this company regarding my Telkom that I’ve settled and Telkom has received payment it’s even reflecting on my current statement. I’ve provided them with proof of payment via email and WhatsApp as per their request however I’m still getting countless threats of being listed at credit bureau. I’ve made calls to them but this is proving to be a waste of time. I can’t wait to finish paying off my phone with Telkom so I’ll never have to deal with them ever again. If there was an option for zero rating or negative I would give them that.