Very selfish corporation

So I made a mistake paying my vehicle twice .I explained this to mfc and sent all the necessary documentation. I'm not in arrears I just made a mistake when doing the payments

Now they telling me yes I will get the funds back maybe by the 16 th... This is nonsense don't they think those funds are actually due for another account or my living expenses. When we owe u it's now or being sued but u can decide when where and how