Call centre agent dropped a call on me

I have just received a call from the above company, regarding a *****ulant account with MTN. she wanted me to furnish the documents that proofs that the account is not mine and I explained to her how I dont see how this is going to help since another company called last year and I send the documents and the account was still not cancelled. I explained to her that I disputed the said account with Transunion and she said I should stop saying that I have refferred the matter to Transunion whereby she even said "whatever" to me(her exact words) and drop the call on me. I dont know maybe it is the culture at this company that their agents can call people and talk to them however way they feel like it and if that is the case they must not call me. I am a law abing citizen and I pay all my dues and don't expect to be treated like a ********.