I've gotten myself into a situation and can't really make a good/fair decision.
Some back story;
I commissioned a fursuit head in the middle of March, the deadline was the 15th of June - so that it would have time to get it delivered to me before a con I would be attending to the 28th of June.
I've received it 10.45pm at the 27th of June, and this is simply because I had to stop by her city to travel to the con. So I ordered the head, she knew the deadline was after 3 months, yet the only reason I have the product is that I happened to be close enough to pick it up in person.
Now, although too late for the deadline I still received a product, but here comes my dilemma;
I know this person as a friend's friend and through some forums, and I know she is still learning how to make suits and that I would be her first "Proper" commissioner. Since it was her first we decided to take payment by half before, and half when i received the product. The money became a problem about a month into the process, she had received half, which was well enough for the materials we had agreed on beforehand, however she started telling me about problems with her not being able to get the materials, and a huge amount of questions of how she should get said materials to her apartment. After a few days of this I decided to simply order the materials for her and have them deliver it to her address. Now I've paid for the materials twice. We did however not change our agreement, and we did not put into writing what would become of the money for materials I had already given her. I assumed it would count as an payment towards the end product, that I now owed less on the final payment. However we did not put this into writing.
She finished the head, but it looks far worse than any other thing she have made. The 4 teeth that are there are brown, the jaw is falling of, there is zero visibility and it's too tight. There is also showing and uneven seams all around the head, some foam showing and the nose seem to be a sock simply glued onto the face with a glue-gun/hot-glue. It is not a product I can wear.
So let's say I paid 2/4 first, then I paid 1/4 for the materials I sendt her, making it 3/4 of the final price. My question is if I should pay the final 4th for a product I cannot use?
One part of me say it's my fault for commissioning someone I know was just starting and therefore risky. However I do not feel I received what I commissioned her for, on top of that she was late for the deadline, and I don't think she would have done the work if I had not ordered the materials for her.
So what should I do with the final 1/4 of the payment? should I simply accept that I took a risk and lost, or should I send her back the head? (I'm not going to ask for any refunds as I know she struggles with the economy), this is is only about the last part of the payment.