Product: Student loan

In XXXX of XXXX I received a call from XXXX XXXX from Lincoln Tech LTI Receivable Division letting me know that I need to start making my monthly payments. I was confused because I never with drew from college they told me that I was placed on temporary out because I was XXXX and it is dangerous to be around chemicals but I agreed to start paying my monthly payment. I was not working at the time so XXXX XXXX set up payment arrangements with me paying {$30.00} every two weeks adding up to {$60.00} per month. I have never missed a payment. As of this year I noticed that the loan was charged off on my credit and started reporting in XXXX of XXXX as a charge off. I then again called Lincoln Tech and asked why would it be charged off if I have been paying. XXXX XXXX stated that the loan has been charged off since XXXX of XXXX. I then asked him why I was never informed and why it was never reported. Then I asked for my balance was and he stated it was {$5000.00}. So I asked how much my balance was when I originally started making payments and it was {$6300.00}. So I asked him why is the balance so high if I have been paying every month on time for the past 3 years. He then told me because I am being charged interest and they just stopped charging me interest. So I asked why I would be charged interest on a loan that was already charged off as bad debit and he then changed his words and said it was just charged off in XXXX of XXXX. So I asked again why would it be charged off if i never missed a payment. At that point I asked to speak with a supervisor and he told me he was on vacation and I asked him for an email he told me that he can give his supervisor a message. So I waited a week then called again and asked if he gave the supervisor the message to call me. He then avoided the questions and stated that his supervisor was in a meeting. So I asked him if he could have his supervisor give me a call back and he said hold on, placed me on hold for 30 seconds then got back on the phone and told me his supervisor said that they can charge interest and said his supervisor was too busy to speak with me and will call me back. I then asked XXXX XXXX to send every payment and document that they had for my account and asked how long it would take to received all the documents and he said he will send it but he did n't know how long it will take. I have not received any documents and every time I call to speak with a supervisor he always answers the phone and states that he in a meeting or something. So my questions are ( Can a company charge interest on a loan that is already charged off because if not I feel that they at least owe me the money back and place it towards my account for the last 3 years of 50 % of every payment interest was paid ) and if they just recently charged me off the next question is ( Can a company charge off a loan that has been receiving payments every month for the last 3 years ) I just feel like this company is taking advantage of students. I have a bill from XXXX XXXX showing my total payment due is {$60.00}. I also have bank statements for the past 3 years of every payment that was made. If someone can please help me with this I really do n't know how any of this is legal. Also I do n't mind making the payments especially since I have never missed a payment for the last 3 years because I do care about my credit very much. I just want to stand up if not for myself but for others that are being lead into this scam. 

Thank you for your time, XXXX XXXX XXXX or XXXX