Is this harrassment or just a bad HR Dept?

**Long post, just trying to be thorough**
A few years ago, I began using FMLA leave to cover days off I needed because of complications with my bi-polar disorder and some troubles my wife has with her conditions. Within in the past year, my employer has suspended me pending termination three times. The first time lasted about a week and was because they stated my doctor listed me has incapable to do my job on the FMLA form. In order to rectify this situation, I had to have my doctor redo the FMLA form and not check mark the one box that was in question. I also had to provide my employer with a note from my doctor that I was able to work without restriction. About two months later, I was again suspended after using a few days of intermittent FMLA leave. The company then stated that the previous FMLA I had covering me was revoked by the note from the doctor said I was able to work without restriction. I was off work during this time for almost six weeks and it nearly tore my family apart. After several meetings with the members of the HR departmant and giving them about two weeks to meet with their own lawyer, they offered to return me to work with no pay. I refused this deal and a few moments later they offered to return me to work with back pay but on the condition that I sign a "last chance" paper stating that I could now be fired for any violation over the next year. Keep in mind, aside from the occasional missed day of work (none that were not excused under FMLA), I have a spotless record and considered an excellent worker by my supervisors. Due to my financial situation at the time, I had to sign the paper just to get money and turn my utilities back on and get my family back in it's home. At the beginning of last month, I filed the paperwork to renew my FMLA leave need. Between the time that I made the request and the time I was given a decision (in which they denied it), I was forced to use a few days off that I mistakingly assumed would be covered. When I was denied, I was not given a reason in the letter I received from my employer. I called the person in the HR staff that is the contact for FMLA and was told that I was denied on my request for self because the same box that was checked last time causing me to be removed from work for a week, was not checked this time. I discussed this situation with the person and was basically given the run around. In reference to my spouses case, I was simply told that it was not filled out correctly. I was not given the chance to have any of the paperwork corrected by my doctor. I was told that I would have to refile yet again from the present time and any days that I missed before that date would not be covered. I am currently suspended under the companies absentism policy because of the uncovered days.
During some of the meetings that I have had with management and HR personal, I have received comments from them that almost seem degrading and confrontational. For instance, in one meeting I was questioned about the medications I use or have used in the past. The exact question was "Why do you take these drugs? These are mind altering drugs!" My response was simply "These are medications prescribed by my doctor, you have a note and why I take them is none of your damn business" In other meetings regaurding my use of FMLA, the statement was made "Your a good worker, well you are when you are here at least." This made me feel attacked for having a disability.
I am not sure of course if this shows a pattern of them harrassing me or simply a pattern of the HR department not knowing how to handle FMLA.
It was my understanding that if there was a problem with the paperwork, the company is obligated to allow me a minimum of seven days to get it fixed by my doctor.
Any help would be appreciated and I thank you for taking the time to read this lengthy post.