A Schengen visa is valid for entry to ANY Schengen country. You have a valid multi-entry visa, so there is nothing stopping you visiting Switzerland or any other Schengen country while the visa is valid.

You are meant to apply for your visa with a country that you are actually planning to visit (main destination, or first point of entry if there is no main destination) - but that's only to spread the workload. Once you have your visa you are free to go anywhere in Schengen, and I understand it is recognised that sometimes people's plans change, often for unforeseen circumstances.

Swiss Immigration may spot the lack of a previous entry stamp and ask about the planned trip to Norway... you may want to have some proof with you to show that you really did plan a trip to Norway and that it got cancelled, so that you can't be accused of obtaining a visa under false pretences.