Woostify theme issue for COD, Add to cart & Page scroll

I have enabled COD in the backend but the cod option is not available on the checkout page. Then after adding the product to the cart from shop page the page doesn’t scroll either up or down, and not able to add further more products because the page is stuck, The mobile menu is not responsive at all. Please tell me the what’s the issue n fix it asap please a humble request.

The page I need help with: [log in to see the link]