Unlike beans, split peas do not require pre-soaking. And yes, if they are too old, they will not soften when cooked. But you've already heard that from the others. I'm just backing them up with a nod as I've experienced the same thing.
As for the integrity issue, and the store manager's attitude, he was wrong. I too belong to a church whose doctrine emphasizes personal integrity in everything we do. And I try to live by it, and have taught my children the same principle. Unfortunately, in this world, there are those who will pay lip service to such values without living them. The manager doesn't know you and has probably been burned by others. He is either untrusting, doesn't care, or is greedy. I wouldn't want to work for him either, as he would make a lousy boss. I agree that you should contact the corporate office. Don't paint the grocery store chain because of one bad manager. Other Kroger's in your town might have treated you much better.
You are the person who was wringed. But you must be the person who has to take the high road and act fairly, to maintaion your own integrity, and to satisfy your own beliefs. I know a bit obut Masonic doctrine, and know that you have very high standards. I aplaud those standards. I wanted to give you some tips for a great split pea soup, but will do that in a post on pea soup recipes and techniques. This thread isn't about the recipe, but how you were mistreated.
In any case, it's all water under the bridge now. Forgive and take appropriate action. Kroger stores isn't to blame, unless they have some type of policy which directs their employees to insult their customers, and I don't think that is the case here.
Oh, and I would recomend getting your split peas from another source as the batch that your local Kroger has may have sat too long in a warehouse somewhere.
I wish you success in getting fair treatment from the store chain. With the letter, you may even find that they send you a check for the items, if you send in the receipt with it. They will probably understand that if you took enough time to contact them, then your complaint is valid.
Seeeeeeya; Goodweed of the North