Are you still receiving calls?
If you still receive unwanted phone calls, you can file a complaint with the Economic Inspectorate.
You can do this:
SPF Economy Directorate-General
Boulevard du Roi Albert II, 16
Meldpunt Belgium: choose “Vervelende telefoontjes”
If you cannot find your question and answer in the "Frequently Asked Questions", you can always put your question to your telecom operator. You will find the contact details of your telecom operator on your invoice or on the operator's website.