It is using 3.5
#hi
serene jetty
The model is hallucinating if it is telling you otherwise.
You certainly cannot sue as there is nothing that you weren't given access to that you paid for. There is no way to remove message limits, message limits are higher for plus users but are not unlimited, this is to control server capacity and is very reasonable. ChatGPT 4 will say that it is ChatGPT 3 or 3.5 since the training date cutoff is september 2021, if ChatGPT 3.5 says that it is 2.5, it is just hallucinating.