Billing for items that must have been collected!

I have spoken to people from your call centre for the past 2 months advising that I no longer wish to have the items. They have continued to call me asking for a payment after I have asked for collection of these items. The heater came to me with a remote that is not working and that has battery outlets that are facing the same side and it does not allow one to change between the different speed levels. I have since spoken to someone advising of this and that i wish to return it all together, they promised to have it collected and to date am still waiting for the collections to be done. Instead when I check my credit profile, you have marked me as unpaid, WHY SHOULD I PAY FOR ITEMS THAT MUST BE RETURNED!!!? I DEMAND CORRECTIONS BE DONE TO MY ACCOUNT WITH IMMEDIATE EFFECT AND MY CREDIT RECORD BE RECTIFIED OR I WILL SUE YOUR COMPANY IF YOUR NEGATIVE REFLECTION AFFECTS ME NEGATIVELY IN ANYWAY!!!