Omnitech Support service from omnitech is worse than having a virus Internet

I signed on with Omnitech for a year. Their services included a monthly "maintenance check" which required that you leave your computer on all night.  This is one of the most foolish things that I have ever done. There was, an still is; an icon placed on my desktop so they have access at any time. I left the computer on as instructed.  I got up at 3 am and saw they had placed a note on the desk top. It said that their maintenance was completed. This is what they had done: Removed all my windows programs which included Access. Excel, Powerpoint, Word and publisher....but no they didn't stop at that. They removed my browser Mozilla, and replaced it with Explorer.  I tried to get back to them and could not make access.  I had a tech on line but was somehow disconnected.  I went back to bed so upset I couldn't sleep. At seven O'clock I tried again and finally got one of their Tech's to help me. I was on the line so long that my blood pressure went so high I could no longer think.  I telephoned my granddaughter and she came over and took over where I had left off.  I am 74 years old and have a heart condition.  Dealing with them nearly put me in my grave. I am active and mentally alert. They had wiped out all the work I had on the computer for a class I was taking at the local college.  When everything was eventually restored I had her ask for a supervisor.  Of course, "There is no Supervisor available." I was determined that I would speak to a supervisor. Later in the day, I called their 800-number and talked to a very nice gentleman who said he was a supervisor. He was sympathetic and said he would see that someone higher up learned what had happened.  When I returned home the next day, there was a phone message requesting that I call them with a reference number given. I attempted to call them and was placed on hold .  I hung up after 25 minutes.  I attempted again about 2 hours later.  The same thing happened.  I was on hold for 30 minutes after I had decided to time my wait.  I finally gave up.  It is 3 o'clock in the morning now.  I thought it might be a good time to try again.  After waiting on line for about five minutes the recording said, "This call cannot be completed. Call again at your convenience."  Don't be as foolish as I was.  Since everything was restored they appear to have been in my computer again.  There have been all sorts of changes made once again. Now I am going to have to hire someone local to get their access Icon off my computer and undo the further damage they have done.