I noticed my radiator was dry after three weeks of driving my car after i got it back from the dealer, they replaced my water pump. I just discovered this tonight after my check engine light came on. Do I have them come pick up my car or should I pay for the tow myself? I am wondering how much damage may and could happen due to their mistake.
It is unlikely that you would be able to drive a car without coolant for three weeks. I suspect what actually happened is that there was a coolant leak, possibly (probably) as a result of the work carried out to your car.
It's likely to have been a small leak and it's taken three weeks for what remained of the coolant to seep away.
What I would say is to stop driving the car immediately. I'd contact the Toyota dealer straight away. If they don't instantly cover the cost of recovery plus any repairs, contact Toyota head office.