Freezing age spot does not seem to be working?

I am a highly freckled fair skin person.  I have developed some age spots.  I went to specialist office but saw the P.A and not the doctor.  She suggested freezing the age spots.  She told me the treatment would be $100 for 15 spots.  She didn't mention that the treatment might have to be repeated or might not work!  Its been four days, the spots she treated are no longer sore, are not blistered, or scabbing and don't hurt at all.  They look really much larger and are very dark brown and very very noticeable.  I don't think the treatment as worked!  Aren't they supposed to blister, then scab, and then the scab begin to fall off in about 4 to six days?  That is what I read on the internet.  That is not what is happening, they look absolutely horrible but are not sore or scabby and don't appear to be going anywhere.  Has anyone had to have age spots treated more than once with freezing before they scabbed and fell off?  The PA didn't tell me I might require more than one treatment and I am definitely complaining to her boss, the doctor, if she says more treatments are required.  I would have never had the treatment at all if I knew this would happen!