Product Filters Not working. and how to add paginate ?

1) Product Filters are not working on my website. please check http://mobilityequipmentshop.co.uk/store/products/
2) how to add paginate ?
3) I have added add to cart button css in custom css, but it only show on home page(red buttons).. but it is showing default buttons on Products List pages
Please check the above link
Thank you