Still happens despite of regulations and it wouldn't be that bad if you just could get the info from person calling you, who got your number and demand removal from database but as you probably know, they love to hang up the second they hear this question. I've heard that the newest trick is to give the victim the premium service number saying "that's how you can get your phone number removed".
Personally, I'm still dealing with periods during year when all 3 phones in my house from Orange are receiving calls from same spam number - two mobile contracts and one landline. I explicitly demanded which was check-marked on my subscriber's account that I do not wish receiving spam calls even if that means my bill is cut by 5 PLN and I'm missing chance to win something (sic!); so it seems even service provider doesn't bother with legislation here.
> they note this down, and call again the next month.
It's probably due to rotation of people - one shift comes in and then next one and nobody cares what called person has to say. It's still a potential "client" for them and the mindset here is "maybe after n-th time they'll gave up and purchase our stuff", I believe
I regularly get a survey call and "congratulations, you won a vacuum cleaner/spa/whatever" call roughly once a month. From time to time, I get some company I'm technically in business with call me (through an outsourced call centre), trying to upsell something useless. I used to get a lot more of calls like these a couple years ago, but I vaguely recall something in the legislation having changed since then, and most spam calls disappeared.
That said, a year ago I started my own business, and now the cold calling just doesn't stop. In Poland AFAIK it's illegal to spam individuals, but it's legal to spam businesses - and now I have, for example, Polcard (card processor) representatives calling me roughly once a month, asking if maybe I'd like a POS terminal. I keep saying them, I'm a contractor, I only do B2B and don't need a terminal - they note this down, and call again the next month.
So currently it all adds up to ~10 +/- 5 unwanted calls a month. It's still usually more than personal calls I receive (but less than personal or business calls I make). Rise of the mobile-connected IMs pretty much put a stop to most personal phone calls among the people I know.