Returned Shoes

Zando delivered a pair of shoes to me that was to big the same day I booked a return of the shoes, this was on the 4/09/2015 which was collected the 7/09/2015. I called Zando on Friday 11/09 to ask them if they received the shoes in their warehouse and they said no. I called again on the 14/09 and they said the shoes hasn't been returned, I called again on the 15/09 and they said it hasn't been returned to their warehouse for inspection. Which means that this is causing a delay in me receiving my money back. I want my money back from Zando because when you buy from them and the size doesn't fit you and you ask them if you can just exchange if for a smaller/bigger size they say no you have to return it to them and they will refund you and in the interim you have to buy the same product and pay them again mean time you wait forever to get your money. At this rate I will not ever order from them again because they don't do proper follow ups with the courier nor with their warehouse department.