Questions regarding speeds and service fees

Last year, we upgraded our plan to the 50mbps download option.  I never pulled more than 35mbps, but I chalked that up to the fact I was using WiFi and didn't worry too much about it.  Most ISP's aren't going to get you the highest download speed that you pay for, so I settled for 35mbps.

Then about a month ago, I realized that our speeds were supposedly "doubled."  So, I decided to connect direct to our rented gateway to see what kind of speeds we were actually getting.  Multiple speed tests showed that we were getting the same as before (~35mbps).  I called the support line and talked to a very helpful rep who suggested I purchase my own modem and router, so I could get better speeds.

I did that, and then checked the speeds again.  They were somehow worse than before, so I called COX again.  They escalated to a Tier 2 rep, who tried some things but ultimately had to send out a tech.

The tech checked some equipment out and noticed that there were a lot of unnecessary connectors in the cable box (which I have no access to).  He took care of that and said that the big problem was due to our being located "at the end of the line."  Apparently, I can't get the speeds that I'm paying for because COX's infrastructure can't handle their customers.  He said that another tech would come out and add a "booster" to our line within a week or two.

Yesterday, I got a letter from COX informing us that we had signed up for a service protection plan of some kind and a few bucks would be added to our monthly bill.  I didn't remember signing up for this, so we called COX.  The rep told us that the tech had actually done us a favor by signing us up for the monthly service protection plan.  If he hadn't signed us up, we would have been billed $60.00.

I'm feeling a little cheated because the tech didn't find any issues with my setup inside the house, nor did he do any work on non-COX property.  I don't believe that it's okay for COX to charge customers any money at all to service COX's own property.  If I had messed around in the cable box or climbed a ladder and destroyed the node or something, I could see how that would be my fault, and I would have no problem paying for it.

It's been a little over a week and I still don't have higher speeds, but I'm holding out until next week before I call up again since the tech did say one or two weeks.

Questions:

Since I'm consistently getting less than half the advertised download speed, should I downgrade to the 50mbps download plan?  If I do that, am I going to only get half of that speed?

Since the issue is with COX's infrastructure and is no fault of my own, can I be credited for the service call, as well as the past few months' worth of below-advertised speeds?

Thanks for reading,

Colin

P.S.  All the reps/techs I talked to were extremely friendly and helpful.  I'm sure it was very frustrating for them to be unable to amend the situation, but they didn't show it.