nokia vodafone 6300

how can i block this person from texting me?
im with vodafone and i live in ireland.I have a nokia 6300 phone- I have been getting texts from a number today that i dont know and i dont know who the person is. I was wondering does anyone know how i can block them because its gettin me down
that happened to me but I am in the states and have Verizon. I called them and gave them the number they blocked it for me. no charge and they credited me for the text’s.
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