Just forget about click fraud,Google discount multiple click from the same IP, however you may pay at the time then get refunded.
The truth is people are clicking and they are not sufficiently interested to pick up the phone.
Look at what you can do.
Increase your QS
set up campaign to give high CTR in first few days.
track CTR
drop underperforming keyword phrases
refine camapign times around peak CT
look at what keywords give a good CT for CPC
rotate squeeze pages to find optimum response (may knock your QS though)
learn your PPC acronyms
or you could try youtube ppc or FB

All this is on the net, I don't know anything about what I've just written