Wits end

Hi there. I had the s4 and loved it. Have the s6 edge now and hating it. My apps don't work properly. Wattsapp sometimes works and sometimes only works when I on the app..have spoken to Samsung and Vodafone. The Internet is so slow I have to restart all the time. Have checked background data, forced stopped, re installed. The works, changed mobile networks. Still no help. I select a number on call rejection. The number can still get through, I don't know what to do or who to contact anymore but this is the worst and most frustrating phone I have ever had. Also. When is a screen protector going to be available? ! Please help me!!!! Tried to contact on your sight and it kept telling me my e mail add was incorrect! So no luck there either.