Product: Student loan

My son is a XXXX XXXX at XXXX University. This is my son 's account. His name is XXXX XXXX. I am helping him by paying the interest on his loan every month. He started at XXXX in XX/XX/XXXX. I made my first interest payment in XX/XX/XXXX, I did this via their website and all went as it should have. I made another online payment in XXXX and was told ( after I sent the money ) that the payment had to go to principal because it was within 120 days of a disbursement, BUT I could call in to make an interest payment. Since then, faithfully, I have called and supposedly paid the accrued interest on his account. In XX/XX/XXXX, I discovered that most ( not all ) my payments had gone to principal, not interest. I called them and after a week of 'discussing ' with various people at XXXX, the payments were adjusted to go against interest. Thinking the problem was fixed, I continued to call in faithfully every month to pay his interest. However, in XXXX, I discovered that, once again, most ( not all ) the payments had gone to principal not interest. I just spent 1 hour and 4 minutes on the phone with 3 different XXXX  employees with no resolution ( most of that time was on hold ). They are now telling me that I have to get my son on the call with them to approve an interest payment every month. This is the first I've heard of this. I am authorized on his account. They are now supposedly going to go back and review the recordings of all my calls because apparently, they were doing it wrong when they did apply the money to interest without his authorization. All payment amounts are what they verbally told me he owed in interest when I called in. Here is the info on my calls, I didn't start keeping notes until XXXX XXXX these are ALL supposed to be interest payments. 

XX/XX/XXXX {$100.00} paid, confirmation number XXXX, name of CS rep not recorded XX/XX/XXXX {$350.00} paid, confirmation number XXXX, name of CS rep not recorded XX/XX/XXXX {$190.00} paid, confirmation number XXXX, CS Rep XXXX XX/XX/XXXX {$170.00} paid, confirmation number XXXX, name of CS rep not recorded XX/XX/XXXX {$200.00} paid, Confirmation number XXXX, CS rep XXXX XX/XX/XXXX, this is the month I went on line to check the account and discovered that most of the payments had gone to principal rather than interest. I called and had a very long conversation with a young man, XXXX I think ( I can't believe I didn't write down his name ), who corrected all the payments to interest including the XXXX payment of {$200.00}. Confirmation XXXX. I naively thought the problem was resolved and would not continue into the future. 

XX/XX/XXXX {$450.00} paid, Confirmation XXXX, CS rep XXXX ; XX/XX/XXXX {$360.00} paid, Confirmation XXXX, CS rep XXXX ; XX/XX/XXXX {$320.00} paid, confirmation XXXX, CS rep XXXX ; XX/XX/XXXX {$250.00} paid, confirmation XXXX, CS rep XXXX ; XX/XX/XXXX {$350.00} paid, confirmation XXXX, CS rep XXXX ; XX/XX/XXXX {$310.00} paid, confirmation XXXX, CS rep XXXX. 

This is when I went on line and discovered that, once again, most of my interest payments had been applied to principal, not interest. I called back on XX/XX/XXXX and spoke with CS Rep XXXX who tried to tell me I COULD NOT make an interest payment on the account within the 120 days of disbursement. So then I spoke with a supervisor, XXXX who told me that she would make the adjustments to XX/XX/XXXX-XX/XX/XXXXand I should check the account in 2 weeks. She also said that " its such a little thing to get money moved to interest ''. The procedure is for the CS rep to apply the payment to principal and send an email to their supervisor to have it adjusted to an interest payment. I informed her that either her CS reps were the most poorly trained CS staff that I'd ever seen before or the supervisors were incompetent if the CS reps were sending the emails. She also stated that she would send a note to their Training Department to have followup training with the CS reps ( which seems to me was her way of putting the blame squarely on the backs of their customer service department. 
I checked the account a couple times and some adjustments had been made but not all of them. However, I got distracted by current events and did not call again until XX/XX/XXXX. 

XX/XX/XXXX. Called and spoke to CS rep, XXXX, who told me the interest balance was approximately {$440.00}, I did not write down the exact amount because I told her that according to the payment history on their website I had made {$680.00} in principal payments had been made and I wanted her to make the XXXX interest payment from the principle they had incorrectly posted. She promised she wound call me back NLT Friday XX/XX/XXXX with a status report. Of course, did not hear from her. 

I called again today and spoke with CS agent XXXX, then to manager XXXX, then manager XXXX. XXXX and XXXX gave me the same song and dance about the 120 days after disbursment. Then XXXX told me that they couldn't make adjustments to the account with out a power or attorney from my son or his verbal approval during each phone call. This information is new after over a year of making interest payments over the phone with out my sons presence AND when I've fought with them before to correct their errors and they did. Now, XXXX is going to listen to all the conversations I've had with various CS reps, ( which is fine, I clearly stated in each conversation that I was making an interest payment ). But she is going to listen to find out where they went wrong in allowing me to apply the payment to interest!! She is supposed to call me back on tomorrow, XX/XX/XXXX by XXXX XXXX  cst with an update. I have NO faith that she will call. 

Can you help me with this.