In short, the answer is No
First of all, as you have correctly stated you cannot exceed the speed limit set by your ISP. This just won't happen. It is a hardware restriction of the connection you are using, whatever that connection is - fiber, ADSL, DialUp, 3g, 4g, ...
A software that claims to overcome the restriction described above is clearly fraudulent.
It is important to mention that there are ways to speed up web browsing to a certain extend. However this is a very special case. You can speed up your browser by rapidly switching between multiple proxies and opening several simultaneous connections to download the same resource. However this is normally offered as an extra functionality with the browser (like Opera's Turbo mode). Yet, even with this functionality enabled, your actual Broadband speed limit remains the top limiting factor.
It is also worth mentioning that there are methods to increase actual data transfer rate. One of these methods is to use compression. However this method does not apply to some dodgy software offering to increase the speed, because compression on one side must be matched by decompression on another. For example if you send data and use some software to compress it, then whoever received the data should be aware of the compression and be capable of decompressing (and vise versa).
Another thing that is very important to note is that there is a very poor regulations about advertising on the internet. Anyone can claim anything about software they distribute, virtually no responsibility is assumed. If it is not a big company with a real name, then no one will really bother with claims.
In fact most of the programs that claim to speed up your Internet will contain either malware, spyware, trojans, advertising or all of it at the same time. By the way same applies for the software that claims to remove all viruses from you PC. Such software is intended for naive people without technical knowledge who will just click "install" and "agree" without giving it a second thought.
If you have asked this question out of curiosity, then I hope I have summarized it well enough for you. This is a good question, btw. If you were actually considering to use such software - don't.