Unhappy with wedding videography production - want expert opinions to provide an independant view
This is going to be a hard one. I am a wedding videographer myself and there isn't really a guild or similar (well there is kind of but there are no requirement to be joined to one in the UK).

Now this is the awkward bit. I am going to assume that you hired this company based on their previous work and that you were happy with how it was filmed, edited and sold to you via phone, email, website, in person, etc AND you have raised the issues with them and tried to get it resolved with them first.

Now assuming the above and the company has filmed your wedding and produced a product that meets the spec provided in your contract with them, it might be hard to take them to court, if they have not produced to the spec described in any of the communications with you and or contract that might have some options within to raise a complaint.

What is actually the problem with the video, is it not like ones on their website or what has been described to you? would you be willing to upload it to the likes of Vimeo and make it a private video for someone to look at?

they would need to know exactly what you are not happy with and or where to look for issues.

Also you might find in the contract there is a statement advising that the creative control with editing is down to the company and not the client or something similar.

I hope some of that helps