extending eligibility and prometric confusion

hello guys,

i have a doubt....i extended my eligibility period for step 1 3 days back..and booked for prometric in my new eligibility period and got confirmed....
i didnt take any appointment in prometrics before in my old eligibility period(this is the first time i took)....so do i have to also pay prometric for extending eligibility(50 usd)..i think that's the fee for cancellation of appointments in prometric right..?
and do we also inform them that we extended our eligibility too(coz i didnt take any prior appointments,thinking should i have to or not...?)

thanks:)