Dear Sirs: I live in Buenos Aires, Argentina but have my social security payments deposited in the US. The bank I use requires a US cell phone number which is the reason I am now an Ultra Mobile customer. I acquired an Ultra Mobile plan in November, 2020. The number is 4793 18 ****. A friend of mine used this number on a cell phone I purchased and sent to his home in the U.S. The number worked. This was approximately in December, 2020. Someone else brought the phone here. It turns on but does not recognize a local network to receive or call the U.S. calling international roaming charges. Can you help me with this situation?