Originally Posted by
drwilliams
The vendor knows he can get paid regardless.
Regardless of what? It's not at all clear (to me) what you attempted to do. If you told the vendor to end the series of preauthorized charges, and further charges were submitted, American EXpress should allow you to dispute those individual charges. If, however, you tried to change your credit card account number rather than deal with the vendor I am not surprised it did not work.