MRP - Snapscan payment not reflecting

I pay my wife's account each month, usually via Snapscan. Last month the payment seems to have not gone through and not showing on MRP's accounts even though I have sent proof of payment from Snapscan. This month's account has now come through showing the new payment, an outstanding payment of the amount I paid via Snapscan, and interest on the outstanding amount. You email MRP and you get an automated email, I eventually had a personal response after complaining about the automated response however still no resolution. This months payment is due again and once again Snapscan is available as a payment option, what happens if the payment does not reflect again????