Paid bill not showing as paid on my virgin media

My bill was issued 17 December, I paid on 20 December via quick pay and received a payment confirmation and receipt of payment number from virgin media but it’s still showing on my account as if it’s not been paid. The due date keeps updating each day and there is a message telling me to pay to avoid disruption. 
I’ve raised a complaint and not received a response and I spoke to someone on the phone who was no help at all. 
Please can someone tell me how to fix this before my next bill is due ??

Thanks!