Configure TKStar TK905 GPS Tracker

Product: [login to view URL] Challenge. To get the gps tracker to report position every 30-60 minutes. Default working mode for this gps tracker is that it reports position every x seconds for 5 minutes then goes to sleep. Have to wake up tracker through sms or call. Then it reports for another 5 minutes then goes to sleep. This behaviour does not work for me. I need reports every 30-60 minutes and preferably have the device shut down gps in between. I can turn off the sleep after 5 minutes through sms. But then it reports position too often. There is a function to set position report interval too but I am not getting this to work properly. Even if I set it for every 1800 seconds / 30 minutes it reports every 1 minute. So please getting this device to report only every 30 minutes :) I have two devices and they both have the same problem.