I am going to implement a "replay battle" button soon. Or an autosave just before combat. One of the two.
Thanks for the pointer though!
Edit: have you placed all 3 members in your team and edited decks? Juggling cards around does wonders. Later cards are often much stronger than your base deck.
Oh, I totally forgot to mention! You can do a manual save once combat begins, even as you're about to lose. Then, when you load the save, it should be at the beginning of the combat encounter!
Not an ideal solution but at least saves you the scrolling