I registered with Silent Callguard too, but it does not work against calls from abroad. The number of silent calls did improve for a while though.Incidentally the silent calls are usually from an automatic dialling system. It dials several numbers at once and connects with the first one to speak. If you say nothing it stops after a short time.
Interestingly, I had a call a few days later purporting to be someone from Silent Callguard offering to block foreign nuisance calls for a "one-off payment " of £29.99, or some such innocuous amount.
I told him it sounded useful and asked for a number to call back when I had thought about it. Checked it later and found it was fake, as I expected.
Offering to protect you against what they are doing themselves is another great scam.
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