A B C Seamless Of Pine Island Inc

I called & made an appt for repair/maintenance issu es regarding windows installed by ABC. They never showed up and now won't respond to my calls/msgs.
In January 1994 ABC installed vinyl windows in my whole house - 13 total. Due to age/weather conditions the screening material is virtually disintegrating/rotting and the screens now have holes, etc. I can't replace the screening because the screen frames have plastic corner pieces which hold them together. I also noticed last year that one of the windows in a bedroom I moved into has cracked at the joint where the top sashing meets the side sashing. This crack is clear through the whole frame and I can see daylight through it and feel air coming in. As a result the window is not square anymore and very difficult to raise and lower, let alone tilt in for cleaning. I am afraid the whole thing will just fall apart and I will have no window at all. I called ABC on 10/3/11 & he called me back on 10/4/11 & left a msg. I called again on 10/4, 10/5, & 10/7 & left msgs. [redacted] called back & I told him I would like to BUY more of the plastic pieces used in the corners of the window screen frames so I can repair/replace my rotting screens and about the one window that is cracking at the seams. He said that windows do that occasionally due to temperature changes and expansion/contraction, etc and they have stuff to fix that. He made an appt for Oct 12th @ 4:45pm. At 4:25pm he called & asked if he could reschedule as his wife had to work late and his kids were home alone. He rescheduled for the next day at the same time. The next day I waited an hour beyond the appt time & when he hadn't shown up I called his cell & left a msg asking if he was still planning on coming as it was an hour past our appt time & could he please call me. I never received a call back. Not ever. Not to this day. I went to Menards to find replacement pieces but they don't work with my windows. I searched on the internet and found many different replacement pieces, but again none are the same as what I need. I do have one window that is on an enclosed porch and was able to use the corner pieces from that screen frame to repair one of the worst ones in the front of the house as they had never been exposed to sun/weather and were not degrading. As a result that window no longer has a screen on it and so I will not be able to open it for ventilation as anyone would be able to go into my porch and just step into my house through the open window. I waited a couple of weeks and then called both the business phone & his cell phone but they still have not responded. At this point they weren't even ANSWERING the business phone and I would have to just leave another msg. If I could just find out who manufactured the windows ABC Seamless put in my house I could perhaps contact the manufacturer directly and get the replacement parts from them. As for the window that is cracked at the joints/seams - I don't know what to do or how to fix it.
I am very disappointed with this company. I bought my home as a single mother of a three year old. I have used my tax returns to make home improvements virtually every year since I bought it. I have had ABC Seamless do virtually the whole outside of my house - all the windows, seamless steel siding/soffit/facia, and most recently a steel roof. I gave them all my business and paid them promptly when the work was done. I recommended them to EVERYONE because I was so happy with the work up to that point. Now I am so discouraged because they won't even respond to my calls when I need help fixing/maintaining the products that they put in my house. My windows look shabby and are becoming non-functioning. I purchased the upgraded quality windows with the low e / argon gas so they would have better insulating value. The warranty states it had a 'limited lifetime warranty'. What does that mean? No warranty at all? There is nothing wrong with my windows except I can't do the maintenance because I can't get the needed parts. I wasn't asking for work to be done for free, but I never expected to be completely ignored either.