Good evening @Nigelino, welcome to the community,
UPC does not offer a fucntion to block some incoming calls. If you do not wish to receive any more marketing calls, you can add your number to the Robinson list. I don’t think it will solve your problem, but this is the unique solution UPC offers.
My parents are also UPC customers and since last July we are also receiving stranges calls once a month from Poland. :smileyindifferent: