Power Home Technologies PRESSURED ME TO GET SYSTEM, LIED ABOUT TERM FEE Internet

I got power home technologies alarm system in May or June of 2011.  The man that came over my house talked me into getting it.  I guess i wasnt strong enough to say no.  Being a single mother of a child with down sydrome, he used that I think to pressure me into getting this alarm.  I understand it was for 36 months at 39.99.  I asked him what was the early termination fee if for some reason i couldnt afford it and he said $375.  After having it 6-7 months money has gotten real tight, child support has stopped and I can afford to pay this alarm system.  Other then each month it starts beeping at 4am telling me system failure.  I called today to check on term fee and the man told me i am still liable for the remaining 29 months at 39.99 = 1,157.  I was not told I would be responsible for the whole 36 months otherwise I would not have signed up for this.  I know that I cant pay that 39.99 for 3 years, especially knowing that my sons child support can stop at any time.  I am so upset now that I am stuck in a situation that I can afford to pay monthly of 39.99 and of course that term fee that I was never told of!!