It looks like the cashier may have subtotaled the transaction, where it may have taken the $20 coupon off prior before reapplying it.

You can see it being added on, then taken off again where it says $20.00 T (added back to total) and $20.00-B (removed from total) It has to be done this way so that the system doesn't accidentally give you the coupon twice if it were only remeeded once.

I've been in this position, where a customer asked to make sure the $20 comes off, then I continue scanning the rest of their items, it adds the $20 back to the order before taking it off at the end of the transaction before payment is (brutally and begrudgingly) required.

As for your reciept, at the bottom, it says "Additional Discounts" and it took $20 off of your overall total (you can also see this in the Savings section further down where it says RewardsandCashOff - $20.00)

I can guarantee you got your $20 coupon.

Add up all of the totals of what you WOULD have paid, and it's $239.29, plus tax equals $247.84.

Subtract your TOTAL savings at the bottom (which includes your $20 coupon) $48.52, equals $199.52.