FIber line not free

Moved into an apartment that already had Vumatel structure. I tried to place an order with an ISP and the ISP tells me that Vumatel tells them that the line is already busy. They even show me the pictures of the Vumatel website denying the order. So Vumatel tells me that the line is free and they can't do anything. Clearly this is Vumatel's fault and they refuse to acknowledge that.