Opencart Add to Cart button now working custom module

About a month ago I paid a freelancer to complete a project for me that will allow me to offer None-subscription products and subscription products on my site for sale at the same time. The freelancer did a good job and created a module that allowed us to process both none-sub and Sub order. The problem is I did not notice there was some bugs in the module that needs to be fixed. The three bugs I would like solved are below. Bug 1. When adding a subscription product ( orange color; sku=fsb ) in your shopping cart and you press continue shopping, and right after you click on a None-subscription product ( sku=not fsb) and you want to add the item to your shopping cart it will not allow you be redirected to the cart. NOTE: This bug can only be seen when client is trying to checkout NONE SUB and SUB item at the same time. How to see the bug: A. Click on this link and add the none sub in your cart [login to view URL] B. Press continue shopping C. Visit this the sub item at this url and add the item to the cart, it will not work [login to view URL] Bug 2. when you add a sub product to the cart and visit the same product details page and push add to cart, the add to cart button will not redirect you to the shipping cart, but if you visit another sub product detail page it will redirect you to the shopping cart. How to see the bug: A. Visit the url link below and press add to cart. [login to view URL] B. Click on continue shopping button C. Visit the same product url above and try to add to cart and you will see the Add to cart button is dead. D. If you try going from step B to the index page and add the same product to the cart from the index page it will redirect you well. Bug 3. When you add a SUB in the cart and press continue shopping button and select a different sub from the product details page not error message will be given to client How to see the bug. A. Add this item to cart [login to view URL] B. Press continue shopping C. Visit and add this item to cart [login to view URL] D. You will see no message will be displayed that you already have a sub in your cart. E. If you try the above steps from the index page add to cart buttons it will work well TEST SERVER READY FOR WORKING