Student loan: Dealing with your lender or servicer

I have loans for each of my XXXX. In XXXX, their grandparents sent XXXX {$10000.00} checks ; one for loan 1 and the other for loan 2. The account numbers were written clearly on the checks and they were sent to the correct location. Mohela endorsed and cashed the checks XX/XX/year>. I provided copies of the cashed checks to Mohela. They have yet to apply the payments and when Ive called they have told me the following : We can not find the funds This is complex We will escalate this issue Please call us When I call they say they cant help me. When I email, they say to call. They say a supervisor will call and no one calls, even after confirming my phone number. Each time I call they say they will escalate the issue, but the next time I call they say it has not been escalated yet. In the meantime, they have continued to charge interest on the full loan amount and will barely talk to me, saying my loan payment is past due. I finally submitted another payment electronically to simply avoid a ding on my credit. Ive asked to speak to the Ombudsman Group, yet no one has contacted me, and I previously filed a complaint through studentaid.gov and they simply repeated everything Mohela stated and that they were working on it. Im at the end of my rope here, and have spent countless hours on the phone trying to get a resolution.