I think the best thing for the “team” is for you to get thrown under the bus.
Now depending on what you do actually, it’s the sales people who the customers have a relationship with. The customer isn’t signing up with the company so much as they’re signing up with the sales person. I have experience in a couple of different industries like this, where the salesman leaves for a competitor and most of the accounts he signed up follow suit shortly thereafter. If the customer needs something done, if they have questions, if they have problems, if they have concerns, if they need a favor, it’s the salesman they go to. It probably helps the company more if they customer fully trusts them, rather than thinking they’re making mistakes.
Unless “customer satisfaction” is part of how you’re graded come review time, it really doesn’t matter, and I think you’re putting your pride in the wrong place to be overly bothered by this. I mean it’s perfectly understandable not to like being blamed, but just realize it’s basically an unwritten part of your job to be blamed for problems, and don’t let it bother you too much. Complaining internally to each other is just blowing off steam to others who understand your plight, I don’t know if I’d view that so much as politics.
Also again depending on how you’re company is actually set up, I would imagine the only boss you and the sales people have in common is the CEO. There’s probably a VP of Sales, and a VP of accounting, and then there’s like 5 different bosses down to the sales team, and then there’s another 5 set of bosses down to the accounting team. So even if the sales people complain to their bosses about you, it probably doesn’t affect you at all. I’m sure your boss knows exactly what it’s like dealing with sales and is fully on your side for the most part. Two different teams, two different set of objectives, two different set of goals, two different hierarchy’s, etc.
Now with that being said, it would be awesome if you have a great relationship with the sales team. But letting them get thrown under the bus to the customer instead of you isn’t the best way to do that.
The one final thing I’ll say is, there’s a lot of good salesmen out there, but some are just jerks. They only care about their commissions and nothing else. They’ll gladly sign up the worst customer for the company, even if they know the company will lose money on them, just to get their commissions. 90% of the sales guys I worked with were good guys, but there were always that one or two that didn’t care about anything but their commission. Dealing with them is just part of the job.