Like any BT based product, there should
be systems in place which allow it to recover in time.
You may have to wait a while, but if you can keep your kids away from the modem, it should go back up (eventually).
been told I should be happy as I was only told I would get 8meg
Simply not an acceptable response (but a typical one, made to get you to go away - which is the whole point of 1st line support).
If you used to get 23Mbps, that's what you should get (not 8Mbps just because that's what the estimator said).
Still; another excellent example of the good service BT provide
ADSL2+ with BE
DL Sync around 4.8Mbps
UL Sync 1088kbps
DG834GT with DGTeam firmware