Probably trying to solve one issue at a time makes more sense -
We need more info for your pairing issue -
Are you trying to pair the Contactless and Chip Reader to your Smart Device?
If yes, which generation Reader - 1st or 2nd ?
If yes, are we talking Apple or Android?
Is your Smart Device running the latest operating system?
Do you have the latest version of Square's POS?
Are you sure your Smart Device is compatible?
Please understand that the volunteers hare are not the same as Tech or Customer Support but, there is quite a bit of hands on knowledge and experience using Square's Hardware and Apps. Sorry for all the questions but, details are helpful for others here to possibly assist.
