This sometimes happens in business, it happens at my office occasionally. Every so often a customer has a bad experience at the beginning, an employee tells them the wrong thing, something takes longer, or the price we quoted isn't possible because of facts we didn't know at the beginning. Then they start flyspecking everything, which just makes everybody nervous and produces more screwups, which in turn produces more flyspecking from the customer.
It's a toxic relationship you have with this company. You're looking to critique them if their install estimate changes by $1.00, which isn't how marine estimates work, it's not a firm bid like in construction. It's almost always just an estimate that's subject to change. The company is trying to muddle across a bridge that's already been burnt, and that's not working out, as you'd expect. Sometimes all the mistakes your employees make in a week land on the same customer. It sucks when that happens, and it's embarrassing, but it does happen and it's not intentional. It doesn't mean they make bad products, or they can't do the job. Just means humans doing human stuff ruined the relationship.
Everybody should just call it a day and you should go with another company at this point. This has reached the point where no matter what they do, you're not going to be satisfied.
FYI I'm not defending them, just as a business owner I recognize this cycle. In my own business when it starts getting here, I just apologize, offer them their money back, and say exactly what I just said to you. Half the time they're like, yeah I see your point I'll chill out, the other half the time they take their money and leave, and I'm happy with that. Life's too short to try and make relationships work when they don't.
like dometic which is gobbling up everything they can retracting our options. That’s also why I prefer ordering from places like Defender, Fisheries or Jamestown instead of West Pro. 
