Oh my god, I had similar problem like you had. I was required to go to a doc for check up for SSI and the interpreter showed up in a weird and plain outfit with ripped/torned black socking. She kinda looked poor or something. She could barely sign, oh god, I was heating up inside of me. When the doctor wasn't speaking or wasn't in the room, she turned and looked at me..... "Jesus loves you", she said for a SEVERAL times. I felt like I want to scream at her! I was gonna say something to her but it seemed like she doesn't know ANY of interpreter policy nor anything. She handed me a small bible. I was being nice to her and thanked her. I went straight to home and called SSI to file complaint. I doubt they would do anything about it!
