How do I activate my Mantano Reader Premium

I have been using Mantano Reader Premium on an android tablet and every time I remove the SD card I have to re-enter the DRM activation code. I kept re-entering this thinking I must need to do it each time I wanted to read my book but now I am being told that I have exceeded my activations. I have uninstalled Mantano Reader and want to try a different ereader but I can't activate the tablet to do this. I am not getting the answer I need from any of the forums. I can't submit a case as all attempts at navigating the adobe site do not lead me to a place where I can do this. I live in Australia and cannot afford to make calls to the U.S.A. to solve this, nor does it seem fair that it is so difficult to have the activation reset. I have only two devices that I use this on, my mac laptop and my android tablet. Could I please have my activation rest or a useful answer to my dilemma.