I don't think any of us is in a situation where we can come up with extra cash anytime we need it. Or else we wouldn't have gotten ourselves into messes with payday loans.
Email the letters if you have an email address. You won't have the proof it was received like you would with a certified letter, but it's better then nothing. Also, you can sign up on efax, and online faxing site, and get a free trial. Cancel before the end of the free trial and you won't get charged. I've done it several times, and I got the free trial everytime, so they seem to let you do it more then once.
There are ways. But you have to want to fight it, instead of using excuses to give up. Maybe I'm being harsh, but other's are going to read your posts and possibly give up too because they see you saying it's too hard and too expensive. I feel like you are looking to rationalize your wanting to giving up by saying it's too expensive. Other's here have not had money to send a letter. The waited. Or they found another way.
What's worse? Spending $10 to rid yourself of payday loans, or paying rollover fees every payday?