they dont ask anything..jus call during the hours listed on the page.
if u have 140 plays they subtract the first 100 and leave u with 40 toward ur next 100.
they take the avg amount bet and give u a freeplay equal to that.
these never expire and sometimes people are surprised when 1000$ or so shows up in there account considering 100s of plays goes by very quick in certain seasons.
-murph