We are all customers here, so can't answer that.
Has your phone actually connected to a US network. (You will need 4G Calling to so.
USA - Roaming with O2
Can only suggest you message O2
Message O2 on
(Facebook) (https://o2uk.co/O2CFB)
X (Twitter) (https://o2uk.co/O2CTW) or
Instagram (https://o2uk.co/O2CIG) ,
They should be able to help you.
This is not O2 and we are all customers here similar to yourself and cannot answer account type queries.
