Consent required but not obtained

I have an old lease that has a clause requiring my consent to transfer or assign any rights. The operator apparently has done a farm out with a different operator and retained an ORRI for their position. The new operator has drilled a well. I have objected but have not been successful getting cooperation out of the new operator. I have been receiving checks. The old operator sent me document recently asking for my consent now. I would like to bring the old royalty interest of 1/6 to a market rate of 1/4. What are my options? I sent the approval back conditional on my royalty going to 1/4 but have not gotten any feedback. It is not large enough to justify a bunch of legal expenses but the lease clearly states written consent is required. Is this just another case of big fish swallows little fish or do I have some recourse?