Thanks for the suggestions. I am gonna go with the BBB option

I am pretty sure it was not a miscommunication as I was requesting to just replace the fuse box without diagnosis. I was persuaded into a diagnosis with the assumption the checking fee will be applied towards the repair.

It is not really the money that matters in this case. I just dont like the fact ppl lie to me. I understand diagnosis takes time, and if they are not willing to waive it, then they should not mention that in the first place.

Like you said, I won't waste my time arguing with those crooks. I would probably end up being quite upset, which is not worth it.