cindyjeans Hello and thank you for your input! I have no experience with e-checks and this was very informative. I can't confirm whether or not that was the case with Nil but, I don't think any money will be coming in as he had confirmed in the screenshots above that it never actually went through. I don't know if it's possible to send money to a cancelled invoice but, regardless, if that were to somehow happen I would definitely refund him. I agree with Pepperly's comment and on a personal note think that the double-checking should have been done around the day that I first informed him I didn't get the payment one day after he claimed to have sent it.
I wish I could have communicated with him further in private since I felt that it was really only the beginning of our messages in my eyes. I felt that if this was truly a mistake on his end we could have at least amended the part in which I had concluded he was lying to me. Even if it ended poorly I don't think a PSA would have even been needed if it wasn't for the copyright claim followed by the block in all honesty. In regards to parts where I had shown screenshots of paid vs unpaid invoices, I included that so that I could show, from my end, that I did not jump straight to conclusions and tried to investigate the matter before I decided to cancel and approach him.
Alter I did not know that and will keep that in mind for the future. Thank you for hoping it gets sorted!
Bruja I really like your advice as well as your analysis of my communication! Thinking back on it I tried very hard to word that I felt he had lied to me the best I could but seeing his reaction made me realize the error in my words. I can see now with how you would have approached it with the sample sentence, that that would have been a much better way to address my concerns. I will remember this in the future and keep in mind how I choose to approach things of this nature;; I'm glad at the very least that the design is not able to be tied to his as many others have said, it is a huge relief. As for the true resolution, I hope one day we would be able to come to something like or close to it since I really wish him no ill will at the end of all this. The miscommunication is exactly as you said at the bottom for me at least. I am worried about him claiming the design and being unable to reach him I feel like this is the only thing I can do to prevent that.