What does ttyUSB mean? Sometimes, the embedded microcontroller does not come with a hardware USB interface. While it is possible to use a software-only USB stack, the additional constraints put onto the CPU and the usually small storage size often lead board designers to include a dedicated UART to USB bridge.
Because of a busy weekend I didn't really follow up other than via emails and this still hasn't been resolved. The consistent word from them was that porting a number sometimes takes 24 to 48 hours.. I spoke to a rep by phone today who promised it would be done within 2 to 4 hours.. It wasn't.
When I ported out of Verizon Prepaid last winter, my account number was my 10-digit phone number, but I opened a chat to get my account's PIN number. I provided my phone number and that PIN to my new carrier and the port was completed in about 10 minutes.