Sinking pavements

Hello, Our 2 years old concrete pavement next to the 80cm retaining wall is sinking.. any one experience a similar issue or know how to remediate ?
https://imgur.com/a/bt7Gr2z
There are visible hairline cracks (After spraying water on the sleepers to see it properly) and slight bending in the bottom concrete sleepers. I've seen these concrete sleepers used to build retaining walls up to 3 meters. I wonder what is it pushing ? The The pavement length is 12 Meters by 1 Meter. Concrete is 100mm. Is it the weight of concrete pushing the sleepers ?
The original concreter doesn't take the responsibility. He has used wacker packer to compact the ground, but since the house is built on a fill he can't compact it any further than what a wacker packer allow.
Insurance claim got rejected too

(doesn't cover soil movement).
The house is built on screw piles, over 1 meter fill.
We are worried this has anything to do with the house footing, even though the the house is built on screw piles, the soil must have sunken so bad that only the screw piles must be holding the house/ exposed. Should we be worried about the screw piles condition and is there is a way to check it out ?
I've done bit of googling and found that Ground Penetrating Radars (GPR) is used for such inspections. Thoughts?
One concreter suggested to remove the concrete and re-do with dow bars attached to footing and the retaining wall sleepers. Will it void the slab warranty ? Does it sound like a solution or is there a better solution to this ?

This will always happen with this construction technique, the fill will always subside with time even if compacted. I’d just accept it. If not then you need a block wall on a footing with slab on top with piers to natural ground through the fill and dowels into house.

You can’t dowel into sleepers or put a slab on them, it’s not designed for that load. You could also use a high strength topping, cement based or epoxy once it has stopped moving but it might crack.

Don’t worry about the house, this issue is the backfill of the wall.