When you move to a small area in Pattaya the people around you will tell other people that now western gold mine have moved in to the area. My friend had a visitor one week from the time he moved in and convinced him it was time to empty the toilet tank.
Sure you need to empty the toilet tank sometimes and there is plenty of companies that make their living doing that. There is a small percentage that only does it for foreigners and to a much higher price.
My friend got charged 3000 THB when the normal price is around 200-400 to empty the tank. Do not think they have some genius solution for your waste they just dump it in the sea or something so the price is just to suck it up.
There is also fake garbage collectors, fake pesticides companies, fake police and many other things. Always ask to take a copy of their ID card or call the tourist police to advice what to do.