Hey there @Han34nah.
Welcome to the EE Community 😊
It would be good to know what exactly has happened here, like @XRaySpeX mentioned, but if it's a case of you making two payments there are a few options you can go for.
Any payments beyond your normal bill will go onto the account as a credit balance.
When your account is in credit you can either leave this in place to go towards future bills, or if you give our team a call they can help arrange for this to be refunded back to you.
Peter
