That is very frustrating, but I understand. Your neurologists are right about the testing, it is expensive and there are not tests for all variants, so can be inconclusive. I refused the testing as well, with the blessings of my doctors. Idiopathic PN is a frustrating diagnosis, it tells you nothing. CMT is progressive and incurable, but gives you something definite to refer to.
Were there things in your family history or childhood/adolescence that supported a diagnosis of CMT?