Assistance on getting line checked for faster uverse internet

I was having issues with my DSL service running slow and dropping connection.  Called tech support and after an hour of troubleshooting, I was offered an upgrade to uverse internet and phone for free with special pricing.  The agent stated that his system said I could only get 3Mbps service.  I told him that both my neighbors could get up to 12Mbps.  All of us are connected to the same box on the pole in our alley.  I gave him the addresses and he confirmed his system showed they could get 12Mbps.  He said we would need to establish the service and then have a guy come out and test the line for faster speeds.  I scheduled the install and when the tech came he said there was an issue with my line back to the CO.  He called a lineman that came out and put me on a different pair because there was an issue with the pair I was on.  I asked him to check the signal and he said I should be able to get up to 12Mbps. The tech completed the install and everything is working at 3Mbps.  Now I am trying to get my service upgraded to 6 or 12 Mbps.  I have done online chat and talked to phone support and keep getting transfered to other people with the same result "The highest speed available in your area is 3.0 Mbps Pro".  I tell them what the original agent said about sending out a person to check for higher speeds, about my neighbors getting 12Mbps and what the guy told me that I could get up to 12Mbps when he tested the line.  I still get the standard answer "The highest speed available in your area is 3.0 Mbps Pro".    I did not know my house was a seperate area from my neighbors house.  Did the first guy lie to me about being able to have someone check\certify the line for faster speeds?

Does anyone know who to call or ways to get AT&T to do what they said they would do?