Not as great as they say they are

Regardless of them really being fast with their approvals and pay outs, I have been struggling to get hold of the accounts departments. First of all, there's no contact us link once you have logged in which is kind of worrying. The real problem is this: on Monday I requested a settlement statement which they sent me, I did the payment straight thereafter (selecting immediate payment by my bank), I sent through the proof of payment and I've heard absolutely nothing. Yesterday, I sent another email with the proof of payment - no acknowledgement of receipt. I spoke to a person yesterday using their online chat, and they assured me that by today it would reflect on my account. I just checked, and the payment has not been allocated. From my perspective I've paid the account and I'm going to instruct my bank to not allow that debit order to go through - why should I pay twice? There's absolutely no response from any of the team members there. And by the way, I manage my own email server so I know what emails goes through and which doesn't. So don't even come with the 'we didn't receive the email' nonsense. I want this issue sorted today please.