Vodacom fibre,unacceptable service

I received an email from Vodacom Fibre informing me that my fibre mbps has been increased at no extra cost, ever since receiving this email early August 2021 my internet connection has been extremely slow after 7pm , I called the Vodacom fibre assist line of which is outsourced,logged a fault of which the log was closed after 4 days without any communication and the issue not resolved.I left a message for a supervisor to call me but 24hours later I still haven't received a call, Vodacom becareful who you outsource you call centres to, this could cost you big time as this service is unacceptable, I suppose Vumatels name is also on the line here due to the partnership,if anyone senior from Vodacom would like more information or to actually solve this small problem,please reach out, your response would be appreciated