I have a problem someone may be able to help with. I have a small number of customers who will be able to collect their items rather than post them so I need to give them a free shipping code & a 10% discount code. Shopify help have said that is not possible to apply 2 codes in one sale but that there are apps that can probably do it. I don't want to put the free shipping the checkout page because we can only do it for a limited number of people. I only need to do this for about 2 weeks until the people have collected their items so I don't need an app for longer than that really. A free 14day trial one would probably suffice..can anyone suggest such an app or a work around within Shopify itself?