[mothered]

If I buy the wrong item on my main account, and buy the item I want to refund on a friend's account, would I get in trouble? Like how does my friend have my item? Thus, it would mean that the item we want to refund would have been sent to me, right?

There are many ways the wrong Item received method works, but I'll only explain just the one as follows.

Purchase the correct Item on your account, and buy the wrong Item on your friend's account and have It sent to his address. The company (seemingly) made an error and packed the wrong Item with your order, hence you received It Instead of your original purchase.