How about a list of call charges in table form, such as an Excel spreadsheet. For example:-
column 1 = code; column 2 = pence per minute; column 3 = included in package indicator
01 X pence per minute - included in call package
02 x pence per minute - included in call package
0344 X pence per minute - not in call package
0345 X pence per minute
The first 2 or 4 digits of the code should be sufficient to identify the charge. The cost per minute could be in 1 or 2 columns as its split between call & connection charge. The inclusion or not in a call package could be another column or two as required.
plusnet (& all telecoms providers) must have this information in a database so that they can bill their customers. So why not publish it in an easy to access and readable form?