Me - "Welcome to Health Insurance Inc, how can I help you?"

Stupid Customer - "You can f*cking well explain hy the f*ck you pri*ks didn't pay me anything back on my claim"

Woah there cowboy.
I bring up the claim - he tried to claim on TOOTHPASTE through his health insurance.
Toothpaste.

Me - "I'm sorry sir, but toothpaste is a non-claimable item"

Stupid Customer - "Bullsh*t. Where the f*ck does it say specifically that you don't pay on toothpaste?!"

Me - "It says in your membership pack exactly what services you can claim on on your policy, then at the bottom it states anything not listed is not claimable"

Stupid Customer - "And that's where you f*ckers f*cked up isn't it! Ha! You have to write down SPECIFICALLY that toothpaste isn't claimable, toehrwise you HAVE TO PAY FOR IT!"

Me - "Well sir, it says there anything not listed isn't..."

*interrupts me*

Stupid Customer - "Are you a f*ckwit or what?! I just f*cking told you, it has to specifically state that toothpaste itself isn't covered! I'm a LAWYER so I know this sh*t!"

OHHHHH the old "I'm a lawyer' line"!
Okay then. That's cool. Let's play it your way then...

Me - "Okay sir, I'm going to lodge a complaint for you"

Stupid Customer - "Damn f*cking right you are!"

Me - "Yes. Now, nature of complaint, disputing rejected toothpaste claim. Contact number [I read the one off his file which he agrees is correct]. And what was the name of the company that you practice law through sir?"

Stupid Customer - "Huh? Why the f*ck do you need that?"

Me - "Well sir, I'm lodging this as a compalint because you advised that you were a lawyer, and we take that seriously, we want to ensure we aren't actually breaching the law in the way we are processing our claims. So in following up with you, our managers here will need to know where you practice law through so we have alternate contact details for you"

Stupid Customer - "Uh....f*ck that, I ain't giving you nothing"

Me - "Ok sir, that's fine. Now the next section we have here... okay, now in your allegation here i just need to note down which Section or Act of the law you feel has been breached?"

Stupid Customer - "Uhhh....just...you just need to pay the f*cking claim okay you f*cker!"

Me - "Certainly sir, we can look into this for you so we can see if this is actually payable or not. Now I'll just need to grab that information from you so I can lodge this complaint for you"

*CLICK*, as he hung up.

Yeah.
That's how I deal with those 'I'm a lawyer!' idiots now.
To date, 100% success rate.
The way I see it, if you're gonna try and pull sh*t, expect to have sh*t thrown back in your face. Simple :)