Asda online different to Instore

I recently searched for pampers nappies and found that Asda had the cheapest price. I clicked on the view link and confirmed on their website. However the price in-store was not discounted the same as the website. So in short it was cheaper to order on click and collect, pay the fee and minimum order charge and have the item picked from the same shelf and delivered to my car in the car park! Be careful with online pricing.