rain soft was sold a system that does not work with out dropping the water pressure east grove village Illinois

I bought a water treatment system  from rain soft in april of last year.I had trouble with it from the start and a mechanic cut my pressure down to 70 lbs  which is not acceptable. our water system runs from 110 to 120 lbs. The salsman did not tell us that the system would only run on 70 lbs. I calld the company and the person told me that all water pressure systems should be run at 70 lbs. I wrote a letter to the company and got a call from the company. The lady said that she would send a mechanic out to see what he could do. It has been a month and no mechanic. I think that I am getting the runaround,and that they sold me a defective system for this township.