I have been banging my head against the wall trying to get ACS to do their math correctly. I had two loans at different interest rates at WellsFargo who sold them to ACS. ACS then combined them into one loan at a mixed interest rate. I call in every month to get the current balance and to make a request as to how to apply my monthly payment (due to my prepaid status). By doing this I will be able to pay off the higher interest rate first and get it paid off quickly. It took a couple months to get the hang of it because no matter how clear you make yourself or how many people you talk to, you must say the magic words "WITHOLD PREPAYMENT." No matter what the person on the other end of the phone says, if you don't say these magical words then nothing you have requested will get processed and they will simply extend your prepaid status by an extra month.
The second problem begins as soon as I start talking to one of the women in customer service who tells me that my balances are $1841.68, $621.11 and $920.84 on 3/9/12. I made a $100 payment ($10.97 of which went to interest) which allows $89.03 to be applied to principal. I call back after the payment has been applied and I get the balances of $1793.22, $604.77 and $896.61. It appears that the correct dollar amounts have been applied. To save money, on 3/9/12, I requested that all $89.03 be reapplied to the loan with the lowest balance and they agree to do so (I even said the magic words this time). Therefore it is understood by both parties that the principal balances WILL BE $1841.68, $532.08 and $920.84. FOUR DAYS LATER on 3/13/12 they say that my balances are $1739.22, $586.56 and $869.61. I don't know if they are dyslexic or just stupid but I'm beginning to lean towards the latter. When I ask why the numbers are different, they say that they don't understand my question because nothing has been applied in the past four days. IF NOTHING HAS BEEN APPLIED IN PAST FOUR DAYS THEN WHY HAVE THE BALANCES CHANGED!?!?!?!? I asked to speak to a supervisor, to which the person responded, "They are not available right now but I'll put in a request to have them call you back." I told her I would rather just be placed on hold until one is available. A couple minutes later Lisa picked up the phone who was just as helpful as the first person so I requested to speak with her supervisor on someone that is capable of doing addition and subtraction, maybe an accountant or something. At this point I was EXTREMELY frustrated and decided to handle it some other time when I had cooled off.
I understand that as an engineer I might have a stronger grasp on math than others but this is not differential equations. I believe that these people are just plain crooked and will do anything and everything to "trick" someone out of extra payments. Watch your account and check back with them every other week to make sure that your requests are being done.