To identify the repeat caller, you need to look at the CLID (if the calling phone is not call-blocked).
Unfortunately, in Symposium database, the only view that keep the CLID is in teh eCallbyCallstat. callbycall feature is not a mandatory feature comes with SCCS.
If your SCCS does not have call by call information turn on. You cannot get CLID info.
Even if your SCCS has call by call turn on, there is no standard report provided by Symposium that allow you to see the summarized information of the call related to CLID.
You actually need to use Crystal report to create special report.
If you want to schedule this report, it is more complicated. Symposium will only allow you to run the call by call report for one hour period only (after you upload the crystal report to SMI and schdule it). Therefore you actually need to duplicate all call by call data into another database server everyday, and do it there.
What you want to do is not an easy task.