N82 Soft and Hard Reset

If you applied the settings you received, deleting the text message containing them isn't going to have any effect.

Note that all these operations but the first will wipe your phone's internal memory so do a backup before proceeding.

First option: revert to factory defaults . Dial *#7780#.

Second option: soft reset. Dial *#7370#.

Third option: hard reset. Switch the phone off and do the following.

1) Press and hold the green "call", "3" and "*" buttons.
2) With those buttons pressed down, switch the phone on.
3) Keep pressing those 3 buttons and only release them once the phone shows signs of life such as the Nokia "hands" logo or the language selection screen.

If you're prompted for a security code, the default on all Nokia phones is 12345 (unless you changed it, in which case you should know what it is).