If you haven't got the operators guide for this phone you can down load a copy from BT's site.  www.bt.co.uk/userguides it works have just tried it takes you straight to the user guide section which saves searching for it on the main page. You will/should find your telephone in the first box. Find it then press  'Go'  and wait while it down loads then up shows a picture of your style telephone.
You say you fitted a new battery and you can only get pulse dialing.  Are you sure the battery is fully charged?. I could be reduced charge as they do say when you buy the unit charge for 16hrs.  I can only say look in the user guide, and if all fails, contact British telecom help line on the number below. They are good and helpful. I know I worked for BT for 26yrs. Unfortunately know nothing about telephones. I was on construction side of BT
 0845- 602 - 1041. BT's help line.
                
 BT BOB
                
 February 2005