How can I change all frequecies in an audio file to 110hz .

That poor support, by which I presume you are referring to the replies you have received here, is provided by fellow-users, NOT Adobe staff.  The fact that you have now cancelled your trial, based entirely on not receiving the "support" you demand, suggests a very truculent user.  Sorry to be so blunt!

The simple fact is that I suspect no-one who visits here actually knows how to do what you are asking!  It is extremely unusual to want "speech", even that generated by a TTS service, to be wholly and exclusively one single frequency. 

In my understanding of the term, such a request goes beyond a "monotone", since any voice inherently includes a multiplicity of frequencies.  In that sense monotone would imply a voice whose fundamental pitch or intonation never varies but will still contian those multiple frequencies.

What you seem to be seeking is far beyond that!  I'm not even sure how intelligible such a "voice" would be.