PnP online shopping is just a disappointment

I have had an extremely unpleasant Pick and Pay online experience. I had no idea that the promotional price "is not guaranteed". Since the money was only deducted the day before delivery - I had no idea that there was a card issue and I was given no chance to sort out the issue. So if there is an issue on the credit card (God Forbid) -no chance is given to you to rectify any bank issues, go to a store to pay cash or use an alternate card so that you get the product at the price you "purchased" it at... PnP will simply cancel your order at the promotional price and as a consumer, you lose out and get no assistance what so ever from ANYONE. After numerous attempts, all the call center agents say is: "I'm sorry. It's your fault that your card declined. The error was not on our side, so there is nothing I can do to help you get the product at the promotional price you were promised... I can put you through to a supervisor or a manager, but they cannot help you because that's our policy and you will have to now purchase the product at the full price". The PnP online shopping/payment "policy" is absolutely horrible. I have shopped online at several other supermarkets and stores and not once have I had issues until now. Especially where no one is willing to help and provide the chance to get the promotional price I "purchased" the product for... I have had my card decline previously. That's not what I have a problem with... my issue is 1: I didn't get a chance to rectify it so I do not lose out and 2: Not 1 person can take responsibility and see how completely unfair this is to a consumer and authorize for this transaction to be processed at the promotional price. I am not impressed at all. This experience has really put me off PnP.