Talk about being judged unfairly

My roommate thinks I gave her space heater to Debbie’s without her permission. However, we already had this argument last year when her new fireplace space heater came in and she sent me and Jackie over to Debbie’s for a second time, actually my third time over there that day.  It just so happened when my roomie was telling me I was a liar Jackie walked in and I said, “hey. You remember when we had to go back over to Debbie’s last week when you were here? What did we go back for”?  And she said, “to drop off the space heater”. 

Now we are having the same fight again because she remembers none of it. She always thinks the worst of me and never thinks she is wrong. Even when I prove it.