with this PrestaShop addon you can easily block unwanted shop vistors. Banned users will not have possibility to browse your website. You can ban them by IP address. Module contains feature to support also masks of addresses like:
more informations about module you can find here:
You can find there only valuable solutions for your e-commerce shop based on PrestaShop engine. Search the best plugin for your store that will meet your requirements and just use it.