Wrongfully handed over to Landou attorneys

I'm having a terrible experience with Planet Fitness, I had made an arrangement with planet fitness to settle my account with them month end August and I did. But during the month I got a message saying my account has been handed over to Landou attorneys, this is happening after I had made the arrangement. I then did settle my account and I called Planet Fitness to find out whats happening, I spoke to a lady and at the end of the call she said everything has been sorted out but I'm still getting calls from Landou Attorneys telling me that I need to pay legal fees even though I settled my account with Planet Fitness, when i tell them to call Planet Fitness and find out why i was handed over even though i had an arrangement with them they tell me they cant which for makes no sense at all, how is it possible you cant contact your own client?