Horrible odour throughout newly settled house caused by rodents

Hi Good People of Legal Advice NZ!

We recently settled on a property whereby there is a persistent horrible odour throughout with the most unbearable case being in the Kitchen area. We are wondering if we have a case against the vendor/agent as we may have to replace the flooring/kitchen to remediate the issue...

We first got a flooring cleaning guy who found evidence of animal urine using a UV light throughout the house. This was initially treated by him with enzymatic cleaners to no avail whereby the odour still persisted. We ended up getting a product called 'odarid' and sprayed it throughout the house with little progress...
The real kicker was when I pulled out the oven and noticed a whole lot of rodent droppings as well as the dishwasher and cleaned this all up to urgently get rid of the toxicity. After noticing it still persisted, we tore out the kickboards and found more droppings to then clean up. We are thinking that the flooring possibly has to be replaced along with the subflooring to get rid of the toxicity/odour.
We have seen evidence of bait stations placed inside and outside the house as well as an unopened pot of bait blocks showing the vendor knew this was an issue beforehand but failed to mention it.
We viewed the house multiple times before settlement and there was no issue at that time until the pre-settlement inspection which unfortunately we didn't raise the issue at that time... Wondering if they managed to mask the smell or the issue happened in between the viewings and preinspection date.

Would we have a case against the vendor/agent to cover some of the costs if we were to have to go down the route of replacing/treating flooring and the kitchen? Appreciate any advice and thank you in advance