Banks cannot be bothered to change small change.
You can either keep them for your next trip to Europe, find a shop that accepts them (there are some near the British ports for example) or give them to charity. Charities collect foreign currency. Banks will change the quantities they will receive.
nah these are hard times i cant afford a renewal. out of work thts why i need to cash in my spare change but it was a nice gesture criminals have plenty cash mind you it is tempting