I'm not familiar with Impulse, but I'd start by looking at CSS classes, having one set that shows up only on the mobile and another that shows up on anything other than the mobile. Try looking at the code that's rendering your page, both on a computer and on a mobile device. Even if the menu is the same links in the same order, it's likely rendering things at least a little differently for each different size. That may point you in the right direction.
Google @media rules if you're not already familiar with them.
If your site is live, it might help people to help you if you provide a link.
www.imjustboxing.com passcode: 0000
on mobile I don't want it to display "SHOP" I want it to show the collections straight away
Mobile view: want to remove that extra layer which is to click on shop for it to display the following collections boxing equipment and clothing