Someone else is in my account

I have emailed and opened mutliple tickets which have been closed, so sorry for placing this here.

Someone else is in my account, I woke up to emails saying 4 new models had been made, I have no idea who the model is and I have not given my details out to a single person. This person is now taking 1000’s of pictures on my account and has access to my training photos, my billing info, and all pictures I took before…

A few days before this, I had cancelled my account, I have the email confirmation, however then it suddenly got renewed & I got charged without me clicking anything.

How should i proceed?