How long does one have to wait for the results of a Literacy and Numeracy test?

I was recently invited by the DWP to sit the Literacy and Numeracy tests for an AO post - tests taken on Saturday 31st January 2009. I am sure that I have ped, but have not received the results yet. The interview was originally scheduled for week commencing 9th February 2009. I rang the main office on Monday 9th February and was advised that the results have not come through yet. It's over a week now, since I completed the tests. Can I ume that I have failed?