Hi,
That is frustrating. I've always had great communication with MartizCX, too. However, they are as human as you or I and capable of making mistakes. They are good folks.
It might be worth calling back and taking a high road. Contact the specific team and ask if you can speak to a project manager. Open by saying that you think you spoke more harshly than you intended (don't blame them for misinterpreting you, even if they did). Apologize and say that you would like to make sure that you are in good standing with them as you have really valued and enjoyed working with them over time.
I have no idea what their internal communications regarding your previous call have been like. When you call, assume the worst, show humility and see what they say. There is nothing wrong with apologizing for something you don't think you did (but might have been interpreted as having done). Your goal is to maintain a business relationship and you may have bridges to repair.
A thought for the future.... I would have approached my initial call with something like this, "Hi, I completed the two shops I was assigned, but was under the impression that I was going to be assigned two that were closer together. I want to make sure that I did the correct shops." This asks the same question you asked, but is completely non-accusatory. It is entirely possible that the two shops were eight miles apart "as the crow flies," but 20 miles apart by driving. Schedulers generally will not know our geography well enough to know that - and it's up to us to verify routes and distances before taking shops.
Hard work builds character and homework is good for your soul.