Harmonix Customer Service Issues

I am experiencing an issue with my purchased songs on Rockband 4 for PS4. Since the Rockband Rivals update, all my purchased songs have disappeared in the game. When I search for them under "Get more songs," it says "no content found." I assumed buying the expansion might restore my songs, but that did not work. I want either a refund for all the songs I purchased or to have all my purchased songs playable again. I feel like this situation is equivalent to stealing. I am eager to have my content restored or receive a refund for the missing songs.

I am having trouble transferring my RockBand 3 songs from my PS3 to RockBand 4 on my PS4. Despite using the same PSN account for both games and consoles, the RockBand 4 game is not recognizing my RockBand 3 song purchases. I connected my Harmonix and PSN accounts to Epic Games too. I reached out to PSN support, who directed me to Harmonix, but since Harmonix was acquired by Epic Games in November [redacted], they are not able to assist me either. Epic Games' support is redirecting me back to Harmonix, even though they are no longer operational. Can someone please help me find a solution to this issue?