Here is the proof of being unable to merge the first account and then being able to merge the second account just fine. I put a charge back in for half the amount I paid for as I explain, even in the dispute, that he provided one working account. The second one seemed to be already merged.
Showing the 2nd account was merged just fine:
This image shows that the first account I tried to merge came back as already being merged somewhere else:
I have done business with other individuals that do this same type of thing and have not had a single issue. I never had an account that couldn't be done.