Possible *****ulent Behaviour

I made an agreement to pay off a gym account with them last year and they called again to re-arrange the payment, which I agreed to. I found out later that I was paying off two accounts - same gym for around the same time. They have confirmed that there were two accounts handed over, I asked for the initial contract for both memberships and they only sent for one, failing to send me the other one yet demanding I should pay. I am suspecting some ***** here, what happens now that I have paid towards both? This has to be *****ulent