ᐅ Water Seeping from Paving into Retaining Wall – Should Repairs Be Made?

Hello everyone,

About six weeks ago, the landscaping contractor built a retaining wall and laid paving stones.
Now, rainwater seems to be rising up through the wall from the bottom. A white residue has already formed on the wall.
Please take a look at the two photos. Hopefully, this will help make the problem clear.
What can be done to address this?
Is the landscaping contractor able to make any improvements?

Best regards