Can't help with company but have had it done here. They must stick a nozzle into the ground and saturate the area with liquid which is pumped from a plastic barrel using a high pressure washer. They will/should want to drill holes in the floor of your house in strategic locations to get right underneath.
These little bustards are difficult to get rid of. If you have a lot of wood inside I strongly recommend getting an annual contract with whatever company you choose to come every month and do inside the house after they have done underneath.
If (the back panels of) your kitchen and bathroom cupboards are affected, and (even worse) the house still has no metal frame but wood beams carrying the plafond gypsum panels, very often the only thing to do is to replace all that wood. Esp. if the house is more than 15 years old, then it really is too late. And that will cost you.
It is a safety hazard; I had the (relatively new, 3 years only) cupboards falling of the wall. And imagine a drywall ceiling panel coming down in a bedroom. Very often they say the (ply)wood that the carpenters buy is treated, but to save money....
We have had Orkin and Bintaro Pest guys over for a look see; both will submit proposals later this week. I will see about getting rentakill to do the same. There is a lower roof addition separate from the main roof structure that appears to be infected. The interior ceiling structure in the front room opposite the infected roof trusses is also showing signs of termite work. We plan to replace both wood superstructures with metal.
The other structures supporting the gypsum and the main roof substructure all appear to be clean. I had all the wood structures treated when we remodeled 11 years ago. The way the house is built each room's ceiling structure is a separate entity. I know termites can tunnel through masonry, but it seems they are so far content with the two areas they have infected. Both companies think they can stop them from getting any further.
Our floors are marble. Again, both guys said they could arrest the progress without drilling the floors.
I have been instructed by istri to hide out during the inspections. You guys all know the drill.
We had quotes of two of those companies at the time and I remember it was approx. 30.000 IDR per m[sup]2[/sup], their approach was very similar. Certain areas could be a bit more, depending on how difficult it was to reach (the ceiling next to the mezzanine was 8 meters high, they had to build a steger to get there).