Disappointing Service

Went to Leroy Merlin Sunday 6/10/2024 They did not have stock of what I required. The manager David did a quote for me there and then. I asked to advise me when the stock arrives, I was advised to rather pay, and I would be guaranteed the stock will be delivered to me on Tuesday 8/10/2024

The goods arrived on Friday 11/10/2024, 4 of the correct size and 4 of a much smaller size of what I order. I did not accept the smaller size goods. Now I cannot get any help. They tell me they have refunded me, great who's banking details have they used. They tell me they will phone me back. This has also not taken place. I explained this was a special order they tell me don't worry. I can place another special order "oh and pay delivery again" and they will deliver the goods. Now I still don't have the goods or my money, but I can place another order.

First experience with Leroy Merlin Greenstone and it will be my last. Any ideas on how to get my money back??