Fat luck on the recording
Despite every IVR system warning me that a call is likely to be recorded I have only encountered actual recordings when the company believes I was at fault. Every single time that the company was in error they deny that a recording was ever made. When the company has been in violation of law and most deserving of a letter to the state's AG they have vehemently denied that any recording was ever made. This in spite of my policy of requesting calls be recorded the second I get an agent on the line.
Record all calls yourself and let the courts sort it out. At the very least, the court of public opinion and the company's PR spin. Notifying the agent that you are recording will likely result in them terminating the call under the guise of not having the authority to consent.
The odds are stacked against you at every turn, especially when you are interacting with regional or national monopolies. If you can't win legally, humiliate them, and see how fast they either cave or double down with a suddenly produced recording that was made after all.