Mineral Purchase Agreement - Can I get out and go with a different company?


Hello, I signed a Mineral Purchase Agreement over a month ago with one company, but then in the meantime I received a higher offer to sell with another company. I contacted the first company and they texted back that they understood and will deal with it with his Managers. I then signed a new MPA with the new company. It’s been a month now and this new company was supposed to close on August 3, but is today telling me they want a signed release from the first company before they can close with me. I have contacted the first company asking for a release and they will not acknowledge me. Any suggestions on what I can do? At this point I just want to sell to either company!