Galaxy S5 useless after update

<p>I was prompted to install the new Lollipop update and did so thinking it would make my phone better as updates generally are supposed to do. Instead I have had endless trouble with the phone restarting randomly, sometimes during calls with clients which is highly unprofessional and very annoying. It also doesn't sync emails regularly as I have selected it to do and sometimes doesn't unlock the screen when I want it to unlock.</p> <p> </p> <p>This is my work tool and before the update I was happy with it. It now affects my ability to effectively carry out my day to day business and this needs to be addressed urgently. Why did Samsung bring out a ****py update that isn't properly rid of bugs? ? !!! I'm not some guinea *** for a new operating system as this is my job and life that is affected negatively. What do you suggest the solution is for this problem? </p> <p> </p> <p>I was happy with the phone until now.</p>