Well, the answer is no. A 23.6" monitor is very close to the size of a 24" monitor, but it is not exactly 24". 0.4" inch is missing; almost half and inch, but not quite.
If you round up to the nearest whole number, then you can say that 23.6" = 24". But there are 23.6" monitors and there are 24" monitors. If you feel cheated, then the only thing you can do is return it for a refund. You can argue "false advertisement". If they give you a hard time say "it is close enough", then demand a refund and ask for just a little more money.
For example, if the monitor costs you $195, then demand back $200 because "it rounds up to $200 and it is close enough."