Welcome to the community!
Any additional funds you might have paid will remain on your account as credit and used towards subsequent bill payments. It should be reflected in your My Account as a negative balance.
Have all of the payments been processed? How did you make payment? If you just made payment and they haven't yet been processed, you might be able to cancel those extra payments.
If the payments have been processed and you would like the monies returned, you would need to contact customer service so that they can refund the excess funds. Alternatively, you might consider sending @FidoSolutions a PM. Once they verify some information, they'll also be able to access your account. You should note that it may take some time for the refund to be processed and returned to you.
Hope this helps 😀