EXCHANGE NEEDED - TERRIBLE SERVICE

I had placed an order for size M11 Bistro Pro Lite ride clogs on the 13th December 2019 (Order no. 51715) and received them on the 27th December 2019. This Item needs to be exchanged for a M10 as this was a Christmas gift. I have been in contact with reception and all Stores (Gateway, Stamford Hill and La Lucia) trying to make an exchange with no luck as they do not stock the item and no help due to the Holidays. As per my telephonic discussion with Nabeela (06.01.2020), I was told that there is a backlog in the returns department and that paperwork will be sent to me (failed). On the 13.01.2020 I called and spoke to a lady by the name of Amanda who took noted my details for a lady by the name of Meegan to handle my query (Still waiting). This is frustrating and disappointing as this was a Christmas gift and now it cannot be used and also it will soon be 30 days from purchase (which will soon be an additional issue).