Cannot find how to contact support to reduce no. of licences

UK based but cannot find any way of contacting support - none of the suggested routes work as I cannot navigate to chat or phone (there is what looks like a US phone number but it says 'not available'). I need to reduce no. of licences and I am now in my renewal window however, even if I follow all instructions online, managing the no. of licences is not available to me as I do not have the option 'View Details'.  Thanks