This Note Claims...

the face value of over USD 87 but is being sold very cheaply; if it's because of being a contraband then why is there a misleading face value. If it's not misleading, where can I redeem $87 from, against it?

It was never issued so it should not have any exchange value. I've send a modification request that might deactivate the display of a currency conversion.

Edit: it was approved but unless it takes an update cycle to take effect, it didn't work.

Even if the note had been issued, the market rate is around 30,000 shillings to 1 USD from what I can gleam from the internet, so it would have a face value of less than $2, not $87.

That would be the black market, like Iran's. I'm discussing the face value shown on the note's page.

Microsoft agrees ~US $88