People who want to have problems with this new system are going to find problems with this new system.

"It charged on the first of the month!" "It charged on the last of the month!" "It charged against my bank account too fast!" "It handled my information too slow!"

Yes, there will be problems, there always are problems, that is what happens if you handle thousands of transactions at once, there will be problems. Just because a problem happens to a superminority does not make the system horrible.