Which exchange will you suggest that has a phone support and good customer support? I am currently using big exchanges such as Coinbase, bittrex etc which has ZERO customer support. They don't have any phone support.
I doubt that any exchange provides you phone customer support. They all (as I know) support customers through email, support ticket or chat.
Phone conversation is bad as it is a challenge for customer staffs to listen to international voice and with such difference in languages, conversation would go void. With customers who have used English as their second language, email, support ticket or chat is best for them.
You have to wait their system and staffs to fill your ticket. If you don't receive answer as fast as you expect, bump your support ticket but please don't create a new ticket. It only create bigger pressure on support system, and you get cons in return.
They restrict user's account without explanation and you can't even contact them!
So, do you use any exchange which has a very good customer support and have phone support? If no phone support then, at least live chat support or very quick/professional email support?
Please check their ToS or FAQ pages and figure out you broke any rule on their platform. Big exchanges only restrict customer accounts if they detect something suspicious, fraudulent things. They don't destroy their reputation with non sense restrictions.