,i used to shop in tesco for many years,i,

Not all stores and staff should be tarred with the same "staff are rude, unhelpful" brush.A large amount go out of their way to help their customers and get very little or no thanks.Perhaps I'm just lucky to have a friendly store.
As for putting the offers up before they have started why not pay for the items that are showing as being on offer then go to customer service for a double the difference refund when they go though at the full price.They'll