Customer getting a "Phone Number Invalid" message at checkout?

[MMHDCafe]

A customer has stated, on multiple occasions, that when she enters her phone number in, a message pops up that reads "phone invalid" or "phone in system already". It won't let her past that screen. She has also stated that if she can get around that screen, after entering in her payment information, a message will pop up that says "payment cannot be verified." If I process her payment through the phone using the same online checkout, I do not experience any issues. Thoughts are appreciated.

[Evgueni]

We process more then 80k/m and the bugs are endless. The customer support has no clue, and we

don't bother anymore to call or report. Just a waste of time. No one EVER followed up on any complain. I'm looking for a new home as well. Not easy to move, we have 1200 items in the system.  

[DailyCultureBet]

I believe the issue I was having is the format. Square wants you to send the number with no dashes and 10 characters. You need the leading 1 for US phone numbers. 

[ExpressiveAesth]

Hello, a customer is having this same issue now. She was able to send me a screenshot and while her email and phone number are entered it states “ a valid phone number must be provided”.  I’m going to set her up with an invoice. Any suggestions or recommendations for handling this in the future?