No, I get that. I had the same thing with my old servicer and it's so hard to keep up with when you're on it and when it's over. Of course if you put it on auto-pay, they are notorious for overdrawing, but never giving the money back. My servicer switch so I got a fresh start.
It sounds as if you also have a financial hardship. I think it's defined as your payment being more than 20% of your Income, so pretty easy to qualify. I don't understand why they are not applying it but FLS can be fickle. Stick with getting then to give it to you; it's tedious but the outcome will be worth it.
In my opinion, forget about using the income taxes. This costs you time. Fill out the income-driven repayment application now, picking a plan. I've found picking the "pick the lowest payment plan" option is a mistake because they often don't do it. It will probably be between REPAY and IBR. Sign it and scan it. Scan 2 of your most recent paystubs with the lowest $ possible. Upload everything to the servicer. This way processes the fastest. The fine print: you only *have* to have your payment recalculated once a year, but you can choose to have it recalculated anytime. So if later your taxes are done and they will get you a lower payment, you can just recertify then. The new payment is good for another year. Have a paycheck where you get a lower amount? Recertify.
Consolation will change your loans to be one big loan on your credit report and I think it will show up as new. With the income-driven repayment plans (which are loan forgiveness plans too), it's very likely your interest will be forgiven. The time estimate for repayment is not accurate because it takes in significant annual pay raises, btw.
It seems like a long road but if you follow the other advice in the rebuild thread, you can improve your other score areas too. It's amazing how many inspiring stories there are.
Don't forget to write down names/ dates/ times. Eventually they will have to fix your account.