One-off payment did show on my account

I paid my final bill on 26 Apr one via one-off payment using my credit card. It has been so many days and I still receive the bill asking me to pay the amount of 343.13 GBP. The payment didn't show up on my account. I've PAID ALREADY and I've triple checked with my bank. They confirmed that the payment is successful. And the payment also showed up on my credit card bill (see the screenshoot I attached)!!! So I assure that the payment has really been successful!!! But I didn't receive any payment confirmation notice till now.

I also contacted virgin through whatsapp. All they asked me was to wait. This was useless!!! I guess they received the payment but they didn't allocate my payment to my account since I entered my postcode and last name when making the one-off payment. There may have so many account holder with same postcode and last name. Anyway, I've already paid but the bill haven't cleared. I'm worrying that this will affect my credit score. It is YOUR GUYS' PROBLEM!!!!

What should I do??? ANYONE can help me check my payment??