Complaint sub-issue: Don't agree with fees charged

RE : Great Lakes XXXX XXXX XXXX XXXX Collection Support I feel like this Company, in question, has improperly mismanage funds through my employer, XXXX, since XXXX, XXXX and also taken my XXXX Federal Refund of and XXXX State Refund of without my knowledge. In addition, they have combined some of my loans without my consent. 
To my knowledge, my student loans are still being service with XXXX XXXX XXXX, XXXX XXXX. XXXX XXXX, XXXX, TN XXXX and maybe under deferment. According to written statements from XXXX XXXX XXXX, my account is in good standing. Current balance is {$0.00}, Past due balance is {$0.00}, Regular monthly payment {$0.00}, Interest rate is 2.33 %. I recently received these reports from Great Lakes and found out that The Great Lakes XXXX XXXX XXXX XXXX Collection Support, is charging an interest rate of 18 %. I contacted Great Lakes XXXX XXXX XXXX XXXX XXXX on Tuesday, XXXX XXXX, XXXX and spoke with XXXX. When I started to ask questions about the interest rate and money taken from XXXX 's, my employer, and combining my loans without my consent, XXXX became furious and hung- up the phone. I proceeded to call back again and someone answered and the phone was hung-up a second time. I then called back a third time and spoke to XXXX. XXXX proceeded to tell me he could place me on a " Rehabilitation Program '' to stop the wage garnishments. He further explains to start the program, I would need to pay a fee of {$890.00} and my payments a month would be around {$5.00}. I immediately thought to myself, this does not make sense. Because they are already taking money from my pay check on a weekly or monthly basis and they have already taken my Federal & State Refund without my knowledge or consent, so why would I need to pay this outrageous fee of {$890.00}. What is wrong with this picture? 
My question to you is ; How did Great Lakes XXXX XXXX XXXX XXXX acquire my loan from XXXX XXXX without my knowledge? How are they able to legally take money from my pay check and Federal & State Refund? Should I have received a letter from XXXX XXXX XXXX? In addition, Great Lakes have combined some of my loans without my consent or knowledge and why are they charging outrageous fees? Why I am still getting updated information from XXXX XXXX regarding my loan? Has Great Lakes broken laws under the " Fair Debt Collection Act? I need further investigation into Great Lakes XXXX XXXX XXXX XXXX - Collection Support- regarding their Unfair Practices. 
I am raising my XXXX years old daughter and because Great Lakes Collection Support has taken money from my pay check since XXXX, XXXX, and to top it off also took the Federal & State tax refund, this has caused a strain in my income and emotional distress. 
I would like for you to further investigate these findings because I have written proof from XXXX XXXX that they still are servicing my loan and it is in " Good Standing '' In Summary ; Due to questionable, improper & unfair practices, may or may not be complying with the " Fair Debt Collection Act '' from Great Lakes XXXX XXXX XXXX on acquiring the student loan from XXXX XXXX, charging higher interest rates, and combining some loans without my knowledge or consent. We ask for a full investigation into Great Lakes XXXX XXXX XXXX Practices.