New shocks and struts noise

So I have a 2012 Prius C. I have been trying to take care of it. Shocks were not in great shape so I took it to a local mechanic and spent 2500 on shocks and struts. (they also sanded the headlights...and took the paint off around the headlights...). Since then I hear a creaking noise like a spring door opening - not all the time but when I go around a corner fast or suddenly. (due to torque?) I also hear a thunk sound, like wood hitting a hollow log when I go over bumps. Again not all the time. Took it back. They didn't hear anything. Took it to another shop...asked them to check and to see if shocks/struts were bad...they couldn't find anything but suggested Toyota. Took it to Toyota - ask them the same thing. They replaced the sway bars which they said were in bad shape. (I guess the first 2 garages missed that!). Another 1200 (had other work done, like an alignment of course). But the car still makes the spring opening sound and the thunking! Not sure what to do next. I was tempted to ask Toyota to take off all the new shocks/struts and replace them and see if they were bad. I plan to take it back to Toyota but I don't want to keep paying for things that don't fix the problem.