bloody hospitals, money suckers

i cannot understand how such a big organisation can continue to behave so obnoxiously!

First I have a surgery, they charge me a huge bill. I pay.

Then I file claims for insurance for the amount that I paid.

The claims went through and I should recieve my $$ back.

Took the hospital 1month to pay me back my $$ nevermind.

But it turns out that my bill was not the final bill yet! HUH???

They said that the amount that is deductable from medisave is an estimate when I got discharged, so they have to wait for the hospital's final bill before the ACTUAL medisave amount needs to be paid.

Fine.

When I try to tabulate the $$ I recieved and the amount I paid, somehow there was a shortfall of $231.xx.

After two rounds of trying to understand this shortfall, I gave up because everyone says one thing different.
medisave amount's claim was lower, so it was not "paid", but wont that be paid by the insurance claim?
surgical cost was an estimate at the point of discharge, so it went UP at the final bill, so I'm paying for something which I cannot claim?

Now, my clinic calls me up telling me that the hospital gave them a shortfall of $231.xx asking ME to top it up!

which means that i'm paying twice for this $231.xx and I cannot understand why?

WHAT THE F**K?

they are lucky I dun have the documents now with me, else I'll go down and scream my lungs out at them! Irritating!