To prove conversation happened between two parties

Sir, I have filed a consumer case against Principal of Private school at Chengelpet court regarding non-issuance of books and uniform on time. I request your valuable advice on following issues: a) Can a recorded call be used as an evidence to prove conversation happened between two parties. Since in written argument Principal has denied such even occured and blamed us as giving false charges against school to claim money illegaly. b) The conversation happened on 29/4/17 is it possible to get call record for authenticity of my claim from service provider. c) Can I request honorable forum to issue an order to the service provider to furnish the logs of the said period. d) If proven guilty can I request Forum to give harsh punishment to Opposite party and opposition counsel for giving false statement/ misguiding court of law / unnecessary extending the tenure of the case. e) If call records cant be retrieved what else can I use to prove it has happened. As I have sent so many letters to concerned official of school mentioning the conversation can be used? f) As per CBSE byelaws Chapter III "No School is permitted to start CBSE Pattern Classes **VI/IX/XI as the case may be without obtaining formal permission of affiliation of the CBSE. Any school who violates the condition would be disqualified for a period of two years". When the school in its advertisement and even in the school board has written CBSE under its name will having standard till VII can be considered as cheating public by giving false information . g) Sorry I forget the article it says that ,"any school who teaches NCERT syllabus without CBSE affiliatioin will be liable to be punished" and in complaint letter to CBSE board about the above school they have given a simple reply " As the school is not affiliated to CBSE we cant take action against them" . In this case I want take the issue to the Govt. about the cheating of public by the school management of false information and collection of higher fees as the case may be in CBSE standard schools. So how to go about the issue. h) How can CBSE board simply gave a one line reply to my complaint letter of brief description forwarded to them for necessary action. If its not under their purview as one of the rule in RTI Act instructs the addressee to forward it to concerned officials for necessary action under intimation to the applicant. As I have asked any RTI query to the CBSE , isn't the basic procedure to be followed in case of any complaints.