Never grew them, But they are a common bush dry bean. Have you been able to grow other common (P. vulgarus) beans? I would suspect a soil disease. You might try direct seeding. Check with your agricultural agent for soil borne diseases in your area.

Peat is pretty acidic (4.4 pH). Beans prefer something in the 6.0 - 6.5 range, so the pellets could be a problem. I agree with farmerdill - direct sow in mature compost and see what happens.