Although this is not as good as an 01/02 number i can give you the code for direct dial to your local abbey branch.
0551143 ****
0551144 ****
replace **** with the branch number as a four digit code, you'll find this on your receipts, instant statements, atm receipts, inside your passbook etc old n&p branches tend to start 1*** whereas most will be 0***.
the 0551144 option is for the manager's phone. nb this does work it's the branch xd number, the branches no longer have 01/02 numbers and as such you'll never get a list of one. and unlike in the past when branches would change their number if it became over used, this won't happen now for ease of comms between branches !
i hope this is useful to you