Pernell, Inc Unethical Vendor: Will not refund money for product they've removed smithfield, North Carolina

Do not use this company.  Pernell, Inc has refused to refund a product that they have already removed from my house (part of a HVAC system).  The company gave a 12 month money back guarantee.  After removal of product, the company stated they'd not give refund until a release was signed  that would resolve them of all future lawsuits - even for other products  still installed in the home.  They wouldn't leave a copy of the release for review and have refused multiple attempts to refund monies and even obtain a copy of the release.  They've attempted to hide behind their attorneys.

They've handled this transaction unethically.   Be prepared to go to court with them, because they are not reasonable.  That is the next step for me.  How can a company remove their product and keep your money afterwards and feel justified?