Toyota doesn't "make" their oil. Some petroleum company produces the oil and slaps Toyota's logo on it for them. Same thing with Motorcraft and Ford. Does your service print-out indicate what oil they used? If so, keep that and report it to Toyota corporate. Tell them you want it changed the right way. Do it yourself from now on, it doesn't take much as far as tools and you know it was done correctly. Use the oil the engine manufacturer calls for, nothing else. You will gradually damage your engine over the long term with that oil in there.

0W-16 is the preferred oil for the RAV4 (and it seems many modern Toyota products). Check your manual. It usually says something like use 0W-16, but you can also use 0W-20 in a pinch, with a caveat. 

You need to change your oil twice as often with 0W-20 than 0W-16. Again, check your manual for the specific frequency for each viscosity. 

So yes, the dealer did screw you over, especially if the car is still under the free maintenance warranty period. But it is not devastating to your engine, as long as you do proper oil changes for each viscosity. 

I agree with @Justin Shepherd.

They can order the oil but the thing is that they do not care since your car is still under warranty and they should change it for free. 

I would be surprised if a dealership service department does anything correctly. Either do your own oil change or if for whatever reason you can't at least have your trusted independent mechanic do it for you.