Truly speaking, I know the pain of getting blocked from facebook. One and half year's back I have faced the same thing you are facing right now. I tried to find a facebook support number or email but I am sorry to say, they don't have one. You can max post a question to their help community.
My problem was way much complicated and I am still waiting for their response. They had a very bad connection between Your own adverts account and Business Manager's Adverts account and they know it very well. So, if you have followed them , you will probably find that they are now automatically merging your own adverts manager and Business manager's adverts account to a single one so that they don't create much problem for future customers.
But being an old customer, I guess they are simply avoiding us and our problems. So, there is no such way you can contact them and get help. But yes! if you are lucky enough, may be someday they will contact you.