I had 2 lines with BT both supposedly giving the same service. One connected at ADSL1 speeds (8Mb) and the other at ADSL2+ (12Mb). When I called to ask them to sort the slower line out I was passed between multiple departments who simply didn't understand the problem. The ignorance of the BT staff I spoke to was staggering. They refused to involve OpenReach because I was getting the minimum speed they were contracted to provide.
I cancelled both lines - moved to AAISP and both lines now sync at just under 18Mb. ON THE SAME PHYSICAL COPPER PAIRS!!!
I feel sorry for so many regular consumers who may not understand some of the ADSL technology and terminology and aren't aware that they are likely getting a poor service because they can't get past BT retail.