Poor service provider 🙄

They installed two lines under my name and account wrongfully, I have been calling querying about the issue with no luck. I cannot pay for two lines cause I'm just renting where I stay and the other line is installed to my landlord. And now i owe money that I don't know, for something I didn't even use. I didn't use any of their line. Please assist me with fixing the issue cause it's now causing emotional stress to me.