Hi there . . .
The worst accommodation I have experienced in Thailand was on Koh Samui.
I stayed for a week at a place called The Windmill, I think, right on Cheweng Beach. It was owned by a Dutchman . . . surprise, surprise !
The location was very good, right on the Beach. Unfortunately, I shared the room with some creature that was covered in coarse hair, and seemed to be about the size of my fist!
I ventured into the shower, and this thing was climbing the wall, headed for the ceiling. I still don't know what it was, but do remember opting to forgo the shower, and had a swiim in the sea instead.
A large centipede (or millipede, I didn't bother to count the number of legs) came steaming into the room under the door, and I decided to ask the so-called manager, who, incidently never left his hammock for the entire time I was there, what to do about this problem.
He advised me, without leaving the hammock, to stamp my foot on the floor, which would cause this thing to roll-up into a defensive 'ball'. I was then to kick it with my foot to cause it to roll outside.
Well, this was easy, I did as instructed, and gave it my best Beckem boot. It worked!
It rolled outside, across the concrete path, and into the room opposite, whose door was wide open. Unfortunately, this was occupied by two highly-strung German women, who proceeded to scream hysterically, and depart their room with great haste.
This was still not sufficient to coax the Manager from his Hammock!
(This prick probably still hasn't left his Hammock to this day)!
I decided to re-locate to a much nicer place called 'High Coral Cove', on the hill between Cheweng and Lamai.
Cheers
Pdm3