State Bank Of India [SBI] — Regarding change in registered mobile number of bank account

The online portal has an option of changing the registered mobile number for a saving bank account by OTP/ATM option, where in the message received on respective phones (old and new) has to be forwarded to 567676 to complete the process. However, one can't submit the relevant information from BSNL mobile network.
In light of this the bank should change this number or sort out this matter which cause lot of inconvenience to the customers