Got fired from work due to a Mixup at my doctors. Any recourse?

I'm not a good typer so i'll just give the facts that I have.

I was diagnosed with a liver disease in february that required preventative surgery to correct. This was Scheduled for the beginning of April.

I filed for and was approved for FMLA at my work in february.

The testing schedule and kinds of tests was daunting and exhausting so in the beginning of March i had contacted my doctor's office asking to be removed from work for the month leading up to my surgery.

Since I have a bad memory I have recorded the call clearly showing me asking to stay out for a month the pre op nurse saying "So you would like to stay out until the surgery" and me confirming "yes" I did not expect anything wrong but I record my official calls because they have lots of information and times and dates for appointments i need to keep.

I get faxed a note from my surgeons office stating "Please excuse "Throwawayla2017" from work so he can prepare for his surgery"

I hand this to HR who knows in advance i wanted to leave early they accept this and I leave work. I fill out the initial paper work for my health insurance short term disablity and stay out of work until april.

Before my surgery is about to happen i have a complication with my GI tract that requires a course of medication to fix this delays my surgery until the May. I am though cleared to go back to work until then since all my other testing is now finished.

I contact my HR department and tell them I wish to go back as my surgery is delayed three weeks. HR calls my surgeon and asks if it's ok for me to go back to work and the surgeon says that the note that was given to me was for only one day and not a month.

HR and legal call me back within a few days saying i had lied to them about the note and they are firing me.

Is there anything I can do? or does this mixup cost me my job? I live in Delaware but work in PA.