If you believe that the publisher is violating your publishing or royalty agreement with them, you could sue them for breach of contract; if you are  right and you win, you could recover the money they would or should have paid you if they had not violated it. That of course might not be enough to justify the lawsuit; to use an example from my own experience (I spent 15 years in educational publishing), an author earned 8% royalties on all sales net of returns and bad debts. Suppose we had mostly discontinued a book--it was still technically being sold, but was unsupportd by sales or marketing efforts The book might only sell $2,500 per year at that juncture; the royalties owed would be only $200; therefore, if we failed to pay an author, while he or she could sue for the royalties, the amount of money to be recovered would be less than court and attorney fees. (The author could not recover more than the royalties he/she should have received.) Therefore, before deciding whether to initiate a lawsuit, consider if it's in your interest to do s.