Beware! This company gives an approximate address and a non-existent UK postcode for their returns. This will probably get there, but will bypass tracking equipment and delay the refund process.
You need to search the Royal Mail postcode-finder and leave off the last letter of the one given - the correct address will then show as a suggestion with unit number, street name and valid postcode. Click on it to appear in an envelope template. This one will work! Do not take the customer advisor's word, however polite their manner.
Welcome to Brazil! (in the Terry Gilliam sense)