1-877-723-3929. I politely asked if it was Safeway's policy to not accept coupons that were higher than the price of the item. She said no. In cases like this the coupon should be adjusted down. So she apologized and talked with my Safeway and then connected me. My safeway also said that my cashier should have adjusted the coupon down and didn't understand what the issue was.
I wish I had asked for a manager while I was there or called while I was in the store but I just wanted to get home. The employees should know the coupon policy as well as their customers.