My Samsung Galaxy S5 has been having numerous issues since installing the most recent software update (4.4.4) . A week ago, my battery would last more than a full day, now it goes from 100% to dead in less than 6 hours. At times it is unresponsive. I have also had problems with missed and undelivered SMS over both wifi and cell. How do I revert back to before the update until these issues are resolved?