B1G1 Coupons on Sale Items at Kroger (Grocery Stores)

I know not everyone has a Kroger, but you can find all the affiliates listed here.  I'd bet you've heard of at least one of the stores at that site.  Anyway, I wanted to tell you about my recent experiences with B1G1 coupons on sale items.  In the last couple of months I've purchased SoBe Lifewater from Kroger a few times.  Every time I've used the B1G1 free coupons I've received from playing the SoBe game here (you can play once a day and print each coupon twice - so 2 coupons a day - I've won every single day).  Anyway, I have received overage because of my coupons every time now (3 times to be exact) and so feel comfortable in saying this is the "truth". Here's what happened yesterday and then I'll explain:

I bought 16 SoBe's (you buy 8 and then get $4 off - it's a promotion Kroger is running).  The original price is $1.49.  They are on sale this week for $1.00 and then after the $4 off they are only $0.50 each.  So when the cashier scans the SoBe it tells you immediately that you are saving $0.49 (from the original price of $1.49) and then after he's scanned 8 of them it takes $4 off.  It looks like a coupon and just is 1 line item saying -$4.00 rather than taking it off each item.  So you would assume that my B1G1 free coupon would take off $0.50 right?  Maybe not since the computer thinks the price is $1.00.  Well guess what?  It took off $1.49 for each coupon.  So I bought 16 SoBe's for a total of $8.00, and used 8 B1G1 free coupons, which totaled to $1.49x8 = $11.92, which means I got all my SoBe's for free PLUS $3.92 in overage.

Like I said, this has happened 3 times now with three different cashiers.  They scan the coupon and then using the computer they find the item it was for and just hit enter basically.  So I've argued each time that they are giving me too much money (I'm trying to be ethical here) and they say that's just the way it is.  So I feel pretty bad about it, but if you think about it, Kroger is actually making money off of it too because SoBe will give them $1.49 for the coupon and they were selling it for only $0.50.  So I should probably talk to a manager before deciding that it will always be like that, but it looks like B1G1 coupons can give you some sweet overage when combined with any sort of sale or mega event because the computer always records the original price of the product.  I'll try to pay attention to this for other products besides SoBe and hopefully I can come up with some definitive answers.  I don't think it's a good idea to email corporate.  I emailed them 2 weeks ago for the policy on how many coupons they would double/triple and a basic coupon policy and part of the email I got back stated you couldn't stack online ecoupons from the Kroger website with manufacturer coupons which we all know that you can, so I've lost faith in corporate when it comes to coupons.  Ok, so enough long windedness for one day.  Has anyone had this happen to them?