I am with tt and when they updated my local exchange it took a few days for the speed to establish and set up. Keep at them and make sure you get past the initial help people as they are just reporters of your problem and can do nothing. The other thing to try is to change your micro filter just in case one is not working properly. If possible you should connect to the master socket rather than through various extensions. I went to one house with a similar problem and found they were connecting through 3 telephone extension cables. Once connected to the master their speed quadrupled.