What locality of garter snake??

[Paul12345678]

Firstly, im new to this forum,so hello everyone!
If possible i am hoping a few of you guys may beable to help me out!?!!
So heres the deal:
i recently purchased a red sided garter snake,from a uk supplier.the image used as the for sale picture was this(attached image) a thamnophis sirtalis infernalis(californian red sided garter)at least thats what it looks like from research and other peoples opinions.
The snake i was sent was this(attached image) seeming to be a thamnophis sirtalis parietalis(common red sided garter)
I just wondered if you guys could calarify for me what he definetely is?
i was sold a snake to me which was not the image as shown on the website,and intend to get back to the company as i feel i have been mislead ,and is some sense not purchased the snake they are claiming they have.
I just want to be sure of what the little fella is 1st!!
any help would be great!
regards
paul