Call center not equipped to support the customer

I have been struggling for 3 weeks now just to get my migrated fibre line working. And after numerus calls to Afrihost the line is still not working. Every time they log a call to Vumatel and Vumatel says the problem is not with them. And back to Afrihost to log another call after a day or two waiting for a response. And then we repeat the process. The questing I have as a client, is how to I get companies working together to service the client if they keep blaming the other company. As a client i am the one needing to pay for service I am not getting.