Buying any free module does not comes with any support guarantee. However it is a standard and well-coded clean PrestaShop module but the developer or thepinac.com will not be responsible if something get wrong during the use of the module.
In case you need support for the module installation and/or configuration you must need to share back-office and FTP access so I can check and fix the issue on your environment. You will get refund of your purchase only if I cannot fix the issue.