Furious with DBT (Dialectical behavior therapy)

The team of therapists and doctors I'm working with currently have referred me to DBT after my therapist retired and I've been waiting since early May. I was told that they had no waiting list so they'd contact me to organise a meeting for assessment ASAP.

They had a few hiccups figuring out which doctors and address I was under as I had recently moved and so I've been waiting without any support despite ringing the emergency services multiple times suicidal until today, they have finally rang and told me my appointment was on the 14th and unfortunately, I was going to be away and asked if I could have it after the 16th.

The woman on the phone was understanding and warm, she told me another doctor would get hold of me to reorganise. Later today, my mother recieved a phonecall from an arrogant man who spoke down to my mother for letting me go away for the week with my best friend and her mother (who happens to be a mental health nurse) and then continued to slate my mothers parenting and tell her I was clearly not ready for the commitment to help myself and attend the appointment, he ended the call after reorganising leaving my mother distraught.

I am so furious.

1. I waited months for their phonecall despite no waiting list and without any support whatsoever.

2. The point of DBT and it's contract is to learn how to live and cope outside of my bed, to show signs of self-help yet when I decide I will put myself out there, socialise and actually have a life, I am knocked back down.

3. He was totally unprofessional and made inaccurate and insensitive assumptions about me and my mother who loves and cares for me deeply.

I have heard multiple complaints about DBT similar to this but I had chosen to dismiss them but after today I've been left more anxious about joining DBT than letting myself and my dreams waste away.