http://quicksms.co.in/how-to-change-smsc-on-iphone-4s-sms-center-number/
Had the same problem, i hope this helps.. Basically just changing ur sms centre number to your current operator.:
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Well this is the way how to change sms center on iPhone 4S
Step 1 - Checking what number is set as your SMS service centre number
Launch your iPhone keypad and type *#5005*7672# and Press Call/OK
You will get a response that tells you the number that has been set as your SMS service Centre number.
Step 2 - Erasing the incorrect SMS service centre number
On your iPhone keypad, type ##5005*7672# and Press Call/OK
You will get a response that tells you that the service centre has no address or something to
That effect. It means it has been erased.
Step 3 - Setting the correct the SMS service centre number
On your iPhone keypad, type **5005*7672*+xxxxxxxxxx# Press Call/OK
You should get a response telling you the number has been set. later there is a notice stating that the smsc successfully changed.
example:
how to change sms center on iPhone 4S
How do I check or change the messaging centre (SMSC) number FOR telkomsel indonesia?
To check the Message Center Number on an iPhone all you need to do is to enter: *#5005*7672#
You will then see:
settings interrogation succeeded
service center address
will then show:
To change the Message Center Number enter: **5005*7672*+6281100000# (for Telkomsel Indonesia).
You will get the same message but if you then check again you will find the new number.