Adversarial or Conciliatory

We deal with an online company a fair bit.  They told us they were sending us a free gift.  We had no idea what it was and yesterday it arrived – broken.  It was a little stand we were to put together but it was bent and one of the wood supports was broken down the middle - rendering it useless on arrival.
The reason I mention it is I have been thinking about our response.  I totally believe we are within our rights to want a replacement.  It is how I go about telling them that is the question I face.
Yet I have for many years done it the same way.  I could be adversarial (our rights) or conciliatory.  I admit my motivation is based on a perceived God thing, but I approach something like this in a conciliatory fashion.
Firstly I try to think of things that will benefit the company.  I personally would like to know if the company I contracted to deliver my goods was handling them with due care.  And if it was me, I would look for a pattern.  Is this experience a “one off” or do such things happen again and again.  If so, I would change contractors.
Then whoever I deal with I treat in a friendly manner.  That way it is win/win.  The person feels like and actually does help, and I get what I want.  I feel that an adversarial approach produces winner and losers.  Stripped back that is like 50% win and 50% lose.  Conciliatory often produces 100% winners.  The company is seen to care about the customer, the person dealing with me feels good assisting another, and I feel good getting the goods.
It has happened that treating people well has not gone well.  I had to involve an ombudsman once.  I was completely straight forward in stating my situation.   They knew I had a case and really went the second mile to get me what I was owed.  Ok it took more than I had hoped was needed but I remained friendly and honest and have found that many people want to aid others when they are reasonable and have a genuine expectation that has not been met.
When I first came to Brisbane I had no idea of streets and I cut off a taxi driver.  He waited in his car for me and then asked me a question I had no idea how to answer.  He asked, “what sort of a moron are you?”  Fair dinkum I had no idea there were types of morons.  I did know though I was in the wrong and apologised.  It was like he had no ammunition.  He just drove off.
Treating others as I would like to be treated often produces wonders.  It seems to me no matter who it is, many prefer to feel good about themselves rather than defensive.  Definitely worth a shot I reckon.