Agent lies

I chatted an agent and asked how much it would be to have a tech run a coax cable to a different level in my house because the only outlet in our house caused bad signal strength where we need it most (I work from home part of the week). He told me it would be $39.99. The xfinity app crashed (twice) before the agent confirmed my appointment, and I ended up calling instead of chatting where the agent told me it would be $100 and said I have the wrong modem for the $39.99 charge (a coax is a coax is a coax, it shouldn’t matter what modem I have). I’m extremely frustrated that an agent misinformed me, and that the internet doesn’t work where I need it to. Will plan to cancel. You guys need to train your agents better, so they don’t lie, or so that others at least accommodate when another agent lies. I have screenshots of our conversation. I’ve had this service one day and I already know why xfinity customer service is rated so poorly.