DSL Connection Problems

I've contacted AT&T representatives through support chat multiple times for this issue. About 5 to 6 years ago we were able to upgrade from Dial-Up to AT&T DSL, we were only offered the slowest connect, but anything was better then Dial-Up. The internet worked fine for about a bit, we got what we were paying for. About 3 years ago we started noticing connection problems. At first we thought they were drops, but they weren't. I use online voice chat with people, and I noticed that at random time for about 5 seconds or so I would not be able to hear the other people, but they could hear me. It wasn't anything to do with the programs being used, it was the internet. I noticed this is anything I would do on the internet. I would get errors from browsers, disconnects from games, etc. I was clueless as to what was happening, I just assumed that we had such bad internet that these problems just came with it. One of my friends seems to be getting the same problems as me.

The first time I contacted AT&T they asked about the router and my setup, and they eventually sent a guy out to my house. He re-grounded our outside house wires, and fixed all inside wires, saying we had a lot of data jumping around in the house. He also said he checked outside and fixed the problems with the connection out there. We saw a small increase in our speed, but still had the problems. I contacted them again, they sent out the same guy. He went over everything again, saying everything should be working, that I was not getting any drops. He gave us an AT&T modem to test things out on, and showed us how to monitor problems with it. We still had problems. Third time contacting them they said we had too many devices using our internet, and that was the problem. Any test they did on our internet turned out clean.

Now these problems I believe are caused by bandwidth. I can easily check for the problems by pinging google.com in the cmd box and waiting to see if I get any "response timed out". When only our computer was connected to the internet I saw no problems. As soon as I connected my phone (or used internet on the computer) and started loading something I saw time outs. I've tested our problems with only one device on the network, so my playstation for example: I used an online game to test this out (as I had a lot of problems with disconnects from online games). The game works fine, good connection and fast, but at times it would just simply kick itself out. It seemed as if when our internet used too much bandwidth that it would simply time out for a few seconds. But it takes very little for this to happen. Someone else in the house can simply be loading a webpage and the time outs happen. These timeouts aren't recorded by the modem as problems, but we all see it with our eyes. I've talked to people and from what I understand is that having multiple devices on the network can cause it to slow down, even to the point where it's almost unusable from the slowness. But those devices should not cause the internet to time out for about 5 seconds. 

I've done pretty much every test there is out there. I believe this to be packet loss. I did a packet loss test and it was clean. I did the same test again, but this time I loaded a separate internet page while it was running and I got really bad data loss. I posted about this elsewhere and got responses about how the road wires could be messed up and data gets lost and gets to me late. My neighbors also have this problem, I've tested it myself. But AT&T claims that my neighbors having the same problems as me means nothing.