Dollar Tree

I had previously purchased two jars of honey roasted peanuts about two weeks previous to the date it had I returned to the store. I didn't saved my receipt but discovered that one of the jars were opened(unsealed). I went back to store #1479 in Beaufort, S.C., where I had purchased it to exchange it. When I told the cashier my problem she stated that she didn't think I could exchange it without the receipt, I asked for the manager, her name was Diane and she came out of the office with a very nasty attitude saying that the policy is, that if I don't have the receipt she wasn't going to exchange it, (With an attitude ) I then asked for the corporate office number and she said she didn't have it, I would have to go on line and get it. I've called the office several times and left messages and haven't heard from anyone yet. I strongly feel that in order for Diane to be in a management position, she at least need to know how to talk to her customers, BECAUSE without the customers she wouldn't have a job. DESPERATELY CONCERN !