My T actually called me the wrong name a few times over a couple sessions. The first time, I had been seeing her for a couple months and she all of a sudden started calling me "Amanda". I was like "it's Sienna". "Oh, sorry! Where did I get Amanda from?"....30 seconds later "So, Amanda"
Wtf?! It's just my name, don't worry about it!

I feel your annoyance!