It appears you're using our cart in full-window mode, where clicking a cart button takes the buyer from your page to another page where the cart is shown in the same window. This suggests that your page-editing software may be altering the cart button code after you paste it in -- specifically, it's removing the target="ej_ejc" attribute in the code which would at least pop open a separate window/tab to display the cart.
If you can find a way to paste in your cart button codes and have them retained exactly as-is without modification, or at least re-add a target= attribute manually, then the button you mentioned in the cart would indeed say "Continue Shopping" rather than "Go Back".