How do I remove this component (adapter) ??

[Captain Scarlet]

Hi learned friends.

A "plumber" has installed a shower for my daughter. However it doesnt look right. This part circled isnt on any pictures I've found of the shower on the internet.
It looks like a hex key may fit the inside?
The picture on the right is how it should look.
I've no idea why the guy fitted it like this.
Any ideas what i need to remove this part so I can replace with the correct part?

TIA.

 

[ShaunCorbs]

Have you got a fixed shower head with a pole as the one looks like it’s for a shower hose and hand held

Should undo

 

[Captain Scarlet]

Have you got a fixed shower head with a pole as the one looks like it’s for a shower hose and hand held

Should undo

Hi Shaun
Yes it's a shower pole and fixed head.
The guy used the pole but put an olive on the pole then a bolt, and fitted it to the end you see.
I

 

[ChrisB1982]

Looks like it should have a blanking cap? Ask this “plumber”?

 

[Captain Scarlet]

Looks like it should have a blanking cap? Ask this “plumber”?

 

[Captain Scarlet]

Looks like it should have a blanking cap? Ask this “plumber”?

He's uncontactable.