It can happen that the word count indicates twice more segments than expected. For instance, you expect 100 words, and you actually obtain in Wordbee a word count of 200 words in total. Please know that chances are that it is not an issue from Wordbee but a typical behavior from Word.
Indeed, when a Word document is saved, and the versions are not compatible, Word itself creates duplicated elements within its' content. This duplicate is created in order to build the former version, the current one, and allow the user to open it in both versions. Moreover, this property is called "Fallback" and occur mostly with documents created with Word 2007. It is then actually correct to translate both versions and therefore obtain a wordcount that reflects both.
Please, ensure that the document's Word version is not outdated to avoid this problem.