Annoyed by Hammond Pole not updating payment made

I have made a payment to Hammond Pole on the 30th May 2019 and instead of my balance going down its just going up. They still claim I have not made the payment this is frustrating and annoying, they have stopped even responding to my emails some of the consultants are just rude and not assisting in this matter. I have provided the proof of payment and almost a month later they still have not updated that i made a payment.