You can always tell when an ISP's support staff are talking rubbish - you can hear a voice on the line.
If you really have an ADSL sync problem (The ADSL light flashes and never goes solid?) you can change the DNS server addresses until the cows come home and you won't fix it. That is because the problem is further down the stack.
First of all you need to eliminate your house wiring. Use the test socket (If you have one or master socket if you don't.) with EVERYTHING else disconnected: telephones, modems, Sky boxes, WHY. If it works then it is your internal wiring at fault. Start plugging things back in until it fails - that will be the problem. BTW ALL devices have to go via a microfilter.
If the above fails them you have a Modem fault (the one in your router), Line fault or DSLAM (exchange) fault. TO eliominate the modem find a spare one and give it a try. Load of people have spares. After that its Talk Talks problem.
If you need more open a NEW post.
t, August 2007