Tech put my connection on a private network among other nightmare visit

So I had a tech come out last Sunday only because of a single channel that I couldn't receive from my cable card device (MythTV - like Tivo). I so regret it. When he arrived he said he was going to have to run a new cable from the pole to my house - due to signal strength at the modem. Fair enough, I thought - although everything has been perfectly fine for the past 20 years. So he comes off of the pole and wants to know where the signal comes into the house. I show him my broadband drop amp and he says that's got to go. I asked why? He says your loosing certain frequencies. Don't try to [Edited: "Profanity"] another engineer. So I go with it. He installs a passive 4 way splitter. Then he wants to know where the modem is. So I show him and he points out that it won't boot up. Hmmmm ... it's been working fine for years until 15 minutes ago. So he installs an Xfinity modem that will be a monthly charge now (I owned the other modem). He says it has WiFi! I already my own WiFi. So I need a working modem obviously. He makes sure I'm good to go on the internet. After he leaves, and I wish I would have looked at my Edge-Lite router before he left, and my ourfacing IP address is now 10.0.0.10! IT's a private class A ipaddress.  Obviously that is going to break my VPN access!! I used to be on the 24.126.202.0 network which I had configured my L2TP VPN to connect to. 

Also after the tech was gone, I found that a ton of channels could no longer be recieved on my MythTV system. So I reconnected my broadband drop amp and got all of my channels back except for the single channel that the original call was for. It's also not good practice to just assume the customer's drop amp can be removed without knowing the cable tv topology in the home, as in how many of what splitters are where in the home. 

There is a tech coming out Saturday. I am going to have to be put back on a routable network which may very well cause my modem to be able to boot up (reached).