Having trouble with your upgrade?! Cant find that Formula to upgrade it?
Formula is awarded to you in the "BONG YOUR WAY!" quest chain! When you complete this, the Formula would have gone into your Giftbox!
Make sure you search here for the Formula and if you find it, make sure to press the USE button to make it count toward your upgrade!
If you can't find any Formula, never fear! It is also GIFTABLE! Get your neighbours to send you some by requesting it from them or sending them some to help em out!