Today, by chance I learnt that some colleagues, from my department, have gone out to buy Christmas decorations and a Christmas tree.
Towards the end of the day, after they had bought everything, they told us that everyone should contribute 10 euros for the decorations and the tree.
Up until then, I thought that the department”s directors were paying for the decorations since there was no prior asking if we wanted to contribute or not.
Also each department gets a monthly “allowance” for general department costs(e.g. buying snacks for guests, buy office supplies etc.)
How do I politely decline?