The parcel service would be more to blame for the wet phone, so being short with Google won't do you any good. More likely Google will eat the cost, and in the end Google will have to dispute it with the parcel service for a refund. (Works in your favor)
Back in the Nextel days, my friend order two phones and had them shipped to his house. Upon arrival he signs for the package runs inside to open them only to find the Nextel boxes inside the package are both empty. He instantly calls Nextel up to alert them to the issue, they're response is (and I'm paraphrasing) "Oh well! Did you sign for the package? It's not our issue, obviously someone stole it during the shipping process and resealed the box" Long story short after months of arguing with UPS and Nextel, Nextel finally agreed to send him replacement phones while they fought with UPS for reimbursement.
My honest opinion on your situation is you need to follow up with Google (as mentioned before, honey attracts more bees) and request a shipping label. Let them know it's been four weeks and you haven't received a label yet. Google being Google should be able to email you a return label, I would ask for it via email just to cut down on time. I feel for you and it does suck, just try to remember Google isn't a parcel service and cannot control what happens during delivery.