Whenever a client asks their radius to be reduced to something which is not possible (such as zero), automatically go ahead and reduce it as much as possible (i.e. to half of the existing radius).  You do not need to wait for their specific instruction to reduce their radius.  It is obvious that they want a lower lead flow so if they qualify for a radius reduction with statements such as any of these below, reduce the radius (if the account qualifies for more than 5 leads in 5 days):

“I am getting too many leads”

“How to I reduce my radius”

“How can I decrease my lead flow”

“I need to stop my leads”