Navient Debt Collection Complaint

Navient Debt collection department,

Non-federal student loan Cont'd attempts collect debt not owed Debt is not mine Mississippi

After reviewing all of my student loans online I realized that I never opened a private student loan with Sallie Mae. All of my student loans are federal and have been consolidated. I only have private student loans with another bank and my dad was the cosigner but never through Sallie Mae. I arranged payments for this account but after reviewing everything this is not my account. I feel I do not owe this bank because I never took out a private loan from them only federal. No payments have been made by me because I dispute the account but the collection agency continues to charge my bank account. I am going to file a complaint with my bank if the payment does not stop. I got confused because I have so many student loans but with Sallie Mae I researched that all of the loans I applied for should be federal never private and are all consolidated at this time.