Absa - Failure to stop transactions

I bought shoes online and asked Absa to cancel the transaction before the money had gone out my account. Absa are refusing to pay as I authorised the transaction. The money sat pending in my account for 2 days. Why did it go through if I asked them to stop it? Now the money is out my account and the company refuse to give me a refund because I think they are ********. I have proof of everything. Absa are dragging this out.