I've tried all sorts of things to stop unsolicited calls in the past but none of them worked. The bodies like the ICO or TPS in the UK are only interested in logging your complaint and then they will investigate when they get so many thousand reports and someone tells them the name of the organisation. If the calls are from another country, forget it, they aren't interested, even if the call routes to a local company after you press 5 or whatever.
So, about a year ago, I bought a Call Blocker device and I highly recommend it. When a nuisance call comes in, press the big red button on the front and no further calls from that number will cause your phone to emit any sound whatsoever.
I do resent having to buy this device, but 20 years after this kind of marketing/scamming became the norm, the authorities have still failed to even acknowledge that it needs to be addressed. In terms of my mental wellbeing, it has already paid for itself many times over!