EG25-G is USSD possible?

Hello. Is the EG25-G module capable for USSD? I have upgraded the module to the latest firmware version and I’m unable, yet, to use USSD queries. The AT command in using (I’m my case to check data balance is *121#) is:
AT+CUSD=1,"*121#",15
Just getting an OK as an answer but nothing more.
Additionally, the module can received SMS but I’m not able to send any.
Thanks in advance for your support.