Hey Ab. I need advice. I commissioned a two character nsfw piece from an artist and when I got it it had multiple anatomical errors. Like the female character in the piece looks like her back has been broken from the way she is positioned, her you-know-what looks not only huge but is off-centered, they also made the female character's legs too big for her body. There are a few small things wrong with the male as well. Would it be in bad taste to ask for the artist to re-draw it or to ask for a partial refund? Any advice would be amazing.

Update: I messaged the artist and politely told them that I was unhappy with the piece and pointed out each thing that was wrong as suggested by a commenter and explained that I would appreciate either a re-draw or a partial refund. They replied telling me that 'Well I am not use to drawing monster/partial human characters. However I will give you a partial refund.
I do request that next time you want a commission from me or any other artist though, to review their work and look to see if they are use to the image you are requesting to save yourself and the artist any undue stress.' and that I should have paid more attention during the stream. (My mistake as my internet was giving out) but they have agreed to pay be back half of what I paid within this week.

In my opinion not being used to a species doesn't excuse the anatomy but I digress.

Thank you so much everyone for the advice.