but mostly it’s the price we pay for the collapse in the cost of communications…
This is utter nonsense. Deregulation and accompanying drops in charges has happened across the EU without the same increase in calls.
Cold calls are an unsolicited invasion of privacy and as such illegal. The infrastructure is already in place to clamp down on the offenders whether they are based in the UK or not. The problem is a regulator lacking both the teeth and balls to enforce the law.
Ofcom should be working to make it easy for people to report offenders and lobbying for fines that will deter companies from risking being reported: not necessarily the company making the call but whichever network facilitates the call. This was the logic behind the changes in the law in Germany last year which drastically increased the fines for cold callers. They also made it illegal to charge customers on waiting to speak to an operator.
My advice to anyone receiving cold calls is to note the name of the company making the call and inform them that you will report them. If you are receiving a lot of abuse then contact your provider and get them to enable tracing (yes, it's already active for GCHQ but you have to pay for it) and get them to do their job in pursuing the offending network. Any costs incurred can probably be reclaimed in legal action and threatening small claims should probably end any discussion. A report to your MP and Ofcom at the end.
If people actually start doing something about the menace then there is a higher chance of the regulator taking notice and possibly even doing their job.