I assume you have you temp permit in hand at this point?
If so, go get your full permit asap. Bring with you copies of your paperwork along with copies of your checks or fees you already paid with the application. You did keep copies of all of this didn't you . When you get to the DPS or State police with proper proof that you applied when the fees were $35 I would guess they would accept that. If not, just be prepared and have an extra $35 with you.
It sucks for everyone, but I guess someone is going to be the last to pay $35 and someone is going to be the first to pay $70. Not much that can be done to change it now.
You have every right to ask that the fee still be $35 for you in my opinion. Doesn't mean the person behind the counter is going to be able to do it for you without you paying $70. So just go SOON and be prepaired either way.