Cost of replacement engine

Hi. I have a 1998 Grand Marquis. The engine needed to be replaced and I had it done, the cost was covered by a third party extended warranty. The repair facility billed 16.5 hours labor for the engine replacement plus 1.4 hours for an A/C evac/recover/recharge. The warranty company would not pay for the 1.4 hours for AC charge as a separate item, they said it should be covered in the 16.5 hours labor time they paid for the engine replacement. The shop sent me a copy of the Mitchell online guide for engine replacement which does not list the AC labor as included in the description of what is included in engine replacement. The warranty company says it is part of the job. I wound up paying $124.00 for the 1.4 hours labor. Should the AC labor have been part of the 16.5 hours or not? Thanks