Product: Student loan

I wanted to refinance my loans with Navient which were at a fairly high interest rate, so I looked into taking a different loan at a lower interest rate. With the help of my parents, I took out a different loan at a lower rate and on XX/XX/XXXX, we went to settlement on that loan. A check was cut at the title company, XXXX XXXX in XXXX, Pennsylvania. The company told us that Navient had a bad habit of getting checks and just holding them. If the check was sent through the US mail, it couldn't be tracked and then interest would just accumulate on the account and I wouldn't be able to trace the check. She suggested we XXXX the check so that we could trace it. However, to do that, we needed a physical address, not a PO box address. ( A PO BOX address is what I was given when I called Navient for the payoff and address. ) So the person at XXXX XXXX called the number on the Navient Website and pushed the zero until we got an actual person. After explaining several times that we needed a physical address for the check we were sending, she gave us a name and address. We sent the check to an address in XXXX, PA. I do not know why they gave us this address, but since we had given the person my name and account number, we assumed they knew what they were doing. I guess it was not the correct address, because we were later told it went to the wrong department. ( In addition to the check, we enclosed a letter with my name, account number, and phone number and told them to contact me if there were any questions or problems with the check. So I don't know why they cashed it if it had been sent to the wrong place. ) After about a week, I realized that the money had not been applied to my loan. I started calling Navient ( which is not an easy task ) only to learn that they had cashed the check but would not be applying it to my loan because it went to the wrong department. I assumed this meant that they would just transfer it to the right department and then apply it. Since they had cashed it, I assumed they would no longer charge me interest since they had my money. They then informed me that they would continue to charge me interest and that it could take up to 8 weeks for this to be resolved. In the meantime, I would still need to make payments and they would continue to charge me interest. Meanwhile, I also had another loan I was now paying on top of the Navient loan. I disputed the logic of this, but they said this was the government 's rule. My mother got involved since she had helped me acquire the other loan and was now responsible for the other loan and somewhat involved in this. She dealt with a gentleman named XXXX ( employee # XXXX ) who initially agreed to expedite the matter and said he would try to expedite the transfer but after doing this would frequently not take her calls when she tried to follow-up on the matter. Keep in mind, this was approximately {$20000.00} we were concerned about, which is a lot of money in our world. My mother made calls to Navient on XXXX ( 1 hour 45 min ) XXXX ( 40 min ) XX/XX/XXXX, XX/XX/XXXX ( called twice ), XX/XX/XXXX - at this point my mother started calling senators. She contacted Senator XXXX XXXX office, who happens to be my senator. XXXX finally called back at this point and informed my mother that the matter should be resolved before my next payment would be due on XX/XX/XXXX. As of this morning - XX/XX/XXXX, the loan is now paid off. However, there is now an overpayment because I had to keep paying on the loan. I do not know when I will receive that money ( the overpayment ). I do not feel I should have been charged any interest after the time that Navient cashed my check. I know they received the check on XX/XX/XXXX. I have proof of that from the XXXX  receipt. I think this entire process was very unfair and designed to take every last possible penny from me they possibly could. Unlike many borrowers, I was a student who faithfully repaid my loan. I never missed a payment and was trying to do the responsible, honest thing. Navient was not acting in good faith. I am looking for simple fairness and hoping that I can save someone else the aggravation that I faced in this process. There has to be a better way. Thank you for your time.