P&P Farrarmere not honoring discounts

Pick & Pay Farrarmere. This is the only P&P I use that does NOT honor discounts on the Smart Shopper app. The cashier actually tried to scan the items individually that made the item I purchased MORE expensive than the shelf price. And after they scanned it, the discount is GONE from the app??? I will much rather go to Oakfields in future.

This is not the 1st time this happens - this happens EVERY time.