Dear Mr Swaminathan, If you are coming from Ernakulam side, then get down at Kottayam. You will get KSRTC bus (2buses are vailable all the times)from the Railway station itself and it is going via Erumeli. I agreed Chengannur is nearest station but train will take exactly one hour from KTYM to CGNR and it is a single line and more traffic also. By that time you can reach pampa from Kottayam (via Erumeli it is 98km). You can save the train fare & time. CGNR is convenient for the people who are coming from Kollam side.
Best regards,
Jayan