Going round in circles trying to find where to complain

[algri-9876]

Hi. I purschased a book ( with two others from other sellers with no probs) with delivery to a pick up point I received a message from the seller asking where it should be sent.I replied that it should go to the pick up point and even gave the full address including the address reference code. I then received the same message from the seller asking where it should be sent, i replied that he should refer to my message. The book did not show as depatched on the timeline. after a week i contacted the seller who said the book had been rejected at the pick up point and was being returned. I visited to pick up the other two books and was told that they had returned the book because there was no address code on the package. they explained that they were not allowed to accept the book without it. I have now been refunded £7.01 and he is saying that i have to pay return cost of £8.99. I i have not seen the book and did not return it. He seems to not understand about the code. I am not happy . can anyone give me some guidance please.
Regards
Alan