I'm having a problem with my publisher not giving me my royalties for two years. They keep telling me the book isn't selling yet I have found used copies of my book on line. How can I find out the number of copies that my book is being sold? Amazon would not give me an answer. There are several complaints about this company in the Better Business Bureau. What can I do?
There is nothing you can do except mandate a lawyer to sue them and force them to disclose their sales figures in the court proceedings.
The relationship between an author and their pulisher is based on trust, which is why the common advice is to only ever publish with well-established and proven to be trustworthy publishers. Except in rare circumstances, you don't want to publish with someone who comes out of nothing. New publishing houses are founded by publishers with experience gained in other publishing houses, so they always have a well-known history in the business. Before you sign a publishing contract, inform yourself of the professional standing of your partner. As an author, all publishers can be considered trustworthy who have books in (multiple) physical bookstores. They will never destroy their business by being dishonest to their authors. Everyone else you need to research well.