How can i get this girl to stop texting me?

I went out with this girl a few times last week, we got on ok but on our last date i realised that it would never work (apart from other reasons i just don't like her) . She obviously didn't think so and wont stop texting me, literally 24/7. how can i let her down easy ? i want it as clean as possible cause her friends and my friends are friends so i will still see her about and want limited awkwardness. Im sure you can understand.