Why no contractor discounts at Lowes?

I would like to know why I can't get a contractors discount at Lowes if I buy $15,000-20,000 worth of material a year from them? I have asked and was told no. 84 Lumber is a little longer drive but at least they are willing to treat me like a valued customer!

I would prefer to buy at Lowes but not unless they are going to change this practice.

Ron Catawissa Pa.