I have recently equipped our MH with a twin Gaslow installation and I now have no need for two 13kg Calor propane cylinders. Both cylinders are now empty so l took them back to my local dealer hoping that he would take both and let me have a Calor Lite for use with the garden BBQ. I then discovered that Calor had a “Cylinder Exchange Policy”. See: www.calor.co.uk/help-and-advice/customer-services/cylinder-exchange-policy. Apparently the policy helps Calor to manage their cylinder stock – or so they say! He would take my empty cylinders if I was prepared to gift them to Calor and take £63.74 off me for a new Calor Lite and new lease. I politely declined and battled my way up the chain of responsibility at Calor until I got fairly near the top. The result was [as you have made such a song and dance about it] we will allow you to purchase a full 6kg for just the exchange price in exchange for the two 13kgs. Through perseverance I will get what I want but it is a one off, but I still rate them as one of the very worst companies to deal with.