Tfg cancelled my order and refuse refund

I’m really ****ed with ur overall service I made a purchase online with sportscene few days later I receive an sms stating that my order was cancelled because u have insufficient stock, and I should go online for refund note, I go to ur website there’s nothing, I write an email and some *********** agent tells me they can’t refund me I need to submit proof of purchase and my bank statement, like what actual f**k, how can one be so stupid it’s an online order, which was made using a bank card so obviously you can refund the debit card that was used making the payment instead of all this *******!!!