Tech installed a splitter at tap and signal went to [Edit: Language]

​Hello,​

​Yesterday (3/23) my new neighbor had xfinity installed and the tech that performed the install put a splitter on the tap in my backyard that is shared between myself and my other neighbor. This tap only has 2 outputs on it, and this tech removed both of our existing (active) connections, installed a splitter and then reconnected both of us to it. He then installed his NEW customer to the other tap port.​

​This has caused signal issues for myself, and I'm sure my neighbor is getting the same levels.​

​Any help would be great.​