Not at all. Zen are quite clear in stating that geographic numbers starting 03 are free and 0345 is not a geographic number
Before shooting off about what people know and don't know, it you take a look at what zen say on the phone service landing page
"Our Line Rental Plus option includes unlimited anytime minutes to 01, 02 and 03 numbers"
Nowhere on that page does it mention geographic and non-geographic numbers.
Get your facts straight before defending zen
BT (poor) -> Zen (excellent) -> O2 (started well, went downhill -> IDNet (No complaints - but 100GB cap) -> Zen (unlimited-and now ipv6!l)