My friend had the similiar situation

like you. After receiving REF, she told her attoney she didn't want to continue the case because she felt the chance to get it approved is small. Her attoney agreed and didn't charge extra money. So she prepared the REF and got approved pretty smoothly.

I guess you need to check out the specifics in your contract with attoney. If it does not say you have to stick with him, then you have choices.

Good luck!