What type of Japanese maple is it? Is the graft below the mulch/soil? As I understand it, some JM's can be grown from seed, but those are less spectacular variaties. The walmart name kind of scares me lol.

Do you still have the tag?
Let's call it a generic "red maple"- Acer palmatum var. atropurpureum, likely grown from seed. Most of the red varieties show green during heat stress, so don't let that throw you.
With careful pruning you can select and develop a new leader on that tree- it will take a few years but it could be rehabbed into a much better shape.

I've looked the thing over very well and even at the very base there's no spot that looks like a graft (unless it healed amazingly smooth). The tag just said "Japanese Maple, Red" on the front and "Acer Palmatum" on the back. No variety description. And I for sure know it had heat stress as I had some singed, browned leaves I had to pluck off, so I guess that explains the green. Thank You! I guess it's all patience and pruning from here on out. :)

I'll make a silk purse out of this sow's ear yet...

The green could also show if it didn't receive enough sun. I have multiple maples that when they first leaf out are green then later change to red.

I received Acer Palmatum 'Orangelola' (spelling?) this spring which was totally green. This is a red variety. After putting it in the sun for a couple weeks, it turned it's normal color.

If no tag and graft union, it was grown from seed. Grafts usually cost a lot more. A grafted maple just at Home Depot would cost around $50+ because of the added grafting cost.

It is possible to root certain cultivars from cuttings. I've heard that 'Bloodgood' JMs are mass produced by cuttings.