As explained in our previous reply, the pStyle option is fully tested and working. We have done a quick test generating 200 DOCX outputs using addText with a custom paragraph style and in all cases the output is correct (the custom paragraph style is being applied correctly). Please test and run the included samples using the trial package.
We'd need to check the exact script you are running and the DOCX output you get when the style is not being applied: if you are using a template, importing styles, creating styles from scratch... Sorry but the trial package doesn't include this kind of support.
We are sure that the problem comes from some error in the code you are running (or your server is caching some content when generating the documents). For further support, if you purchase a license, please send an email to contact[at]phpdocx.com with a DOCX output that illustrates your issue and we'll be able to help you.