Interior cable/ slow internet

I have started with VOO this year, but I am facing problems with the internet speed. The technician that made the connections said that the cable that brings the signal into my apartment causes the problem, since the signal up to that point (outside my flat) looks perfect. 

Is VOO responsible for changing the cable (less than 10 metres), because right now I am paying for a service (fast internet) that I don’t get.