I've been with customer service for more than 8 years now and one of the intensive training and experience I've been through was with Iron Mountain - Data Management where we handle all queries from CEO, COO and other upper hierarchy of a company (all means - includes billings and in terms of legal inquiries where we assist the customers with regards to contracts).
I believe that this experience made me and lead me to where I am right now, where I am one of the top rated - freelancer in Upwork.
In addition to that, I've been with dropshipping company for more than 3 years now and I handle most of the admin task which includes processing refunds, handling chargeback and special request from the customers