This is going to sound harsh but is not personal: I am sorry that you were not able to read all of their Terms & Conditions before travelling. Had you have done so, you would have understood their way of working and would not have paid the punitive charges. It is true that FR's Ts&Cs are different to other airlines but that is how they run their business (and do so very successfully).
Since you state that you will not be using them again, you may not want to read all the helpful information here:
http://www.pprune.org/passengers-slf...ts-merged.html
By the way, 'friends would have advised me to cancel', you would then have found that you cannot cancel a Ryan Air flight!