My Order online has been not delivered they cancel it without contacted me, I just receive an email they tell me about the refund and no stock on their system . How come the system allow me to place an order if there is no stock and they deduct my money.

On the 15/04/2022 I have placed an order for the Urn Logik online , they send me an email says my order was successful they deducted money on my account . On the 21/04/2022 I receive another emails says they order has been canceled they will refund me the money back within 2 working days , My order was suppose to be delivered on the 22/04/2022. I contacted their head office they told me it was out of stock but when i did that order there where stock , I just need that Urn I don't need any refund . Their service was not helpful at all. I am not happy, I send them emails to query about my issue 1 lady contacted me so i explain to her she say she will tell them to rectify the mistake till today still waiting. Please assist me.