Bad and delayed service with incorrect delivery specs provided

I bought a refurbished laptop from them on 30/09/2021, paid for overnight delivery.

They promised to deliver on Monday the 04/10/2021. They kept me waiting and waiting and stopped returning my calls.

I finally received the laptop on 08/10/2021, only to have confirmed the incorrect RAM was delivered on the upgraded specs. They promised to correct their actions today, 11/10/2021 and did not return my calls or arrive today.

I have emailed them and what's apped them only for no response.

Shocking service in my opinion. I hope this reaches them to correct their poor service immediately otherwise do not support them.