My in laws have just changed our wedding plans to something i don't want what should i do?

He (or she) who holds the purse strings gets to call the shots. Simple as that. When you allowed your future in-laws to take over paying for your wedding, you gave away control of what that wedding should be like. Your second problem is the fact that your fiance has no spine. The time for him to "leave talking to them about wedding details" to you is over. He needs to man up, talk to them and tell them that their money and input will no longer be required, that you and him will pay for your own wedding and go back to your original plans.