Complaint for Poor service

I have experience poor poor service from Telkom SA its really frustrating for the service provide not to provide the service as they adverting , I signed up contract in December 2018 for 10G router @ R139 per month but my debt order went to R159 i enquire about that still the matter has not yet resolved. December 2019 i got boom R654 debited on my account ??, I send numerous messages they reply"Hi Yoliswa, we have escalated your query to our Mobile Billing team for further assistance. Feedback will follow." I am still waiting .