Afrihost cannot honour their word

In 2018 I was a Afrihost customer and switched fibre providers from OpenServe to Vumatel. I asked the consultant if installation costs would be covered and has telephonic and email confirmation that Afrihost would cover costs of Vumatel. I was contacted in 2019 from Vumatel asking for payment. I produced the email and email / called Afrihost explaining that I have an email to prove that I am not liable for installation costs. I thought the matter was resolved in 2019. During this week, I received emails from Vumatel asking for payment. Afrihost does not listen and support is unhelpful. I have PROOF that I am not liable what else is needed. This is the reason I am no longer an Afrihost customer.