Used them many times and have had no problem - ever. I always get what I expect, and take note of what I have signed up to. I travel light and don't pay for any of their extras that I don't have to. Ignorance of what you have been told when you make your booking is no excuse, indeed, it is just laziness on your part. Sorry, but you only have yourself to blame, and are hopefully now more aware of how Ryanair operate and can base your future travel decisions on this knowledge.
I don't particularly like them, and I detest O'Leary and his management team with a passion on so many levels, but if they provide what I want, at a price I want, then I'll use them. The fact is though, that quite often they are not the cheapest when you take everything in to account so it pays to shop around and do your sums. As a result, I haven't flown with them for about 8 months, since other airlines have offered a better deal or almost the same price deal but with a better service and terms and conditions at the time. It's your wallet, so do your homework and make the choice that's right for you for any particular trip.
Sorry, but there is nop way in hell that Prestwick should be described as a Glasgow airport.
Why not ? Distance to city centre is around 28 miles .. same as Gatwick is for London. Train takes 40 minutes .. quicker than tube takes from Heathrow to central London (Heathrow Express is extortionate). Travel by car in to Glasgow is quicker than trying it from ANY London Airport (except perhaps London City). You sound like a Glasgow Herald reader
Other airports in their network don't pass the same tests, but Prestwick being tied with Glasgow is as relevant as any of the airports used by London.