ISP left me with more questions than answers, need clarification

Yeah, I would ask for his supervisor. Its not that he pulled a fast one on you, it doesnt seem like it. But it seems like he just wanted to finish his job quickly so he can go to his next appointment, and maybe he was short on time (no way for me to know that) or maybe he wasnt, but it seems like he was just fulfilling his obligation to do what is required and nothing more.

Anyway, your ISP's support should cover this hole, and should answer all your questions but....not all ISP's are the same, some have amazing helpful support, and some have a support that you need to beg to get even vital information out of them.

So, I will try to answer your questions to the best of my ability:

[Why aren't we getting what we paid for? (300mbs "ultimate" web package)
"you need to be hard wired to the modem to get even close to that speed"]
- Does the 300mbs refer to internet bandwidth? If so, then even though you dont need to be hardwired to the router to get that speed, realistically you wont get with a Wi-fi connection.
There's also the Wi-fi speed, Wireless-N will go up to 600mbs, but not realistically. In practice you're looking at fluctuating speeds of 300-450 at best, and that is with the best hardware and setup. Obstructions and interference will always have a hit at your wi-fi quality and speed.
There's a lot more that can be said here, but I will stop for now.

[I am hard wired. I'm only getting around 50mbs max.
"You need ethernet drivers, you clearly never installed them. (proceeds to take shots at my computer)"]
- Well, I have no idea what he did to your computer, but typically no ethernet drivers = no connectivity with ethernet devices. Speed has nothing to do with it here. Unless you werent connected via an ethernet cable, but instead used USB connectivity, which is terrible and a lot of routers dont even support it. So you were able to connect and your router device was working right? So ethernet drivers wasnt the issue, and you already had them.

[Why is my 5G connection slower than my 2.4ghz connection then? my 5g is 15-20mbs but my 2.4 is around 40mbs.
"Because your adapter isn't dual band, name brand or AC."
My adapter is name brand, it's TP-link.
"When you connect a 2.4 connection to your modem it'll slow down your other connections to that speed. It's either that or one of the other things I mentioned"
Okay so what can I do to get the speeds I'm paying for then?
"Upgrade your hardware. Your computer looks old. I don't even recognize it."]
- I put this all in 1 bracket pair, because this is 1 exchange where the guy is clearly being evasive and his replies are either wrong, or downright irrelevant.
Your computer hardware has nothing to do with low speed, or connectivity issues. Your network hardware is what matters, as well as the environment and setup you are stuck with.
He is right though, that too many wireless devices connected using the same band (2.4) will result in lower speeds for each device.

Let us make this clear now:
There's network (LAN or WLAN) speed and quality, and there's internet (WAN) speed and quality.
You seem to have problems with mostly WLAN connectivity.
If you experience too many disconnects and poor speed on your wireless devices then its simply a problem with the wi-fi that you're facing, and your ISP shouldnt be responsible for that. In fact, your ISP is the last party to blame for this. Unless your ISP offers Home Network support and hardware, in which case they are to blame and should offer the support they promised. But I dont know of any ISP's that do that, so hmm.

I could go on, and try to offer solutions, but I wanna make sure that:
A) You understand all this that I'm saying and,
B) I am not misunderstanding you and the problems that you are facing.

So I am waiting for your response before I offer anything more.