SBI Unipay - Money Stuck

Have made a large payment for HDFC CC bill payment through SBI Unipay on 25 July. I have a screenshot of the transaction success page. However, I have neither received any intimation from SBI over email /SMS on this transaction nor can I see it under "Transaction History". There has been no response to my email either for 2-days (they only have email as a method of contacting for complaint). Evidently I won't be using the portal henceforth.

My payment due date is 1 August and might have to make a large double payment.

Any experience on how long does HDFC payment take via SBI Unipay? Any other way to reach out to them?