It might be an issue with the wiring in your home. If you have a modern-ish type phone connection, unscrew the wall plate where the phone line first enters the property and you should find a phone socket inside into which you can plug your home hub direct - thereby eliminating your home wiring completely. If performance improves (as mine did) get a techy to check your home wiring. In my case a fractured wire was found and bypassed giving some modest performance and considerable reliability improvement.
If (also like me) you're over c5 miles from phone exchange you will probably have to live with a slow B'band connection until BT upgrade your local exchange to new technology. Also, fyi I've given up on wifi and run a cable from the hub to my secondary pc in our spare bedroom. This made all the difference. Hope this helps. If not be assured you are not alone in living with frustratingly slow broadband but it is still better than dial-up.