Digital Ovulation Test not working

I am using the digital ovulation kit. I get cramps, when my surge is starting along with a few other signs. I tested yesterday because the cramps had started and no smiley. Cramps are worse today so I tested again and no smiley so I tested with a cheapie test with the same urine and got a positive. I can send you a picture of both tests side by side. Why is this test not detecting my surge and can I get my money back as I am very irritated about the amount of money I spent on these tests to have them not even work.