"..." can mean a number of things, learn about them here!
We're aware of an issue where Android users experience their messages stuck on '...'.
Our team is investigating this and we hope to have a fix ready for you soon.
In the meantime, try logging into your account on an iOS device, sending a message, and then logging back into your account on your Android device. If you don't have an iOS device, try borrowing one from a friend or family member.
When you login to your account on another device, it will reset your account on your device and clear your chat history. So make sure to read any new messages first! Your list of saved contacts will still be there when you login to your account again :)