processor speed

That processor, like other Intel i-series CPUs, has a normal ('base') speed and also a 'turbo' speed at which it can run at for short periods if it needs to cope with a high workload. That model, the core i5-6400 has a normal speed ('base frequency') of 2.7 GHz and a 'max turbo speed' of 3.3 GHz. Thus it would be difficult to say that you were 'taken', although the base speed is usually used to describe a processor. Often the turbo speeds are used in advertising as 'up to' speeds, e.g. 'up to 3.3 GHz'. Some people might say that this is misleading, but then again, processor information is very widely available on the web, for example at Intel's site, and a sensible buyer would possibly check these things before parting with money. If you bought it in the firm belief that it had a base speed of 3.3 GHz you could try to get some money back, maybe, but a lot depends on what the machine was described as in sales documents, advertising etc. Personally if I was happy with the computer's performance and I had paid a reasonable price, I wouldn't bother, but then I would have known exactly what I was getting before I ordered.