I CAN RECIEVE CALLS BUT I CAN MAKE ANY CALLS?

Do a hard reset on your phone

It can be the settings issue.Click the link below to reset :----http://technoanswers.blogspot.in/2012/02/unable-to-make-calls-or-send-sms.html
--------Thanks.

You can only make international calls when you have subscribed to it. please contact the helpline of your service provider for it.

Hello:

You need to restore factory settings of your k800i . your phone default code is 0000, go to setting then select restore setting or factory setting and enter code 0000 .

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good luck .

U may need to reformat it ie. Jailbreak and unlock. But thats if its out of warrantee,

go to settings ---> call barring ---> then click on Data calls ----> cancel .

this should enable sms send and recieve.

I accidently locked my boyfriends sgh-t429 Samsung and i need to unlock it quick!

I flashed and flexed the set but to no avail, tried a software update but no update was available from motorola. I then went to the Security settings of the set and restricted all outgoing calls and restricted all incoming calls except the phonebook entries. Then I dialed my mobile using a landline which was on my phonebook and my phone started recieving the calls, then after that I allowed all incoming and outgoing calls. This solved the problem. I believe it is sheer luck because I tried that step earlier on the same day but it gave no result.

what you can do is a master reset and master clear on the phone.

Its problem in the network, try to change some settings.