put up with non payers waisting my time

Wasting what time? It takes seconds to issue a reminder or an invoice with a pay up message (I have a form paragraph that is copied and pasted), another couple of seconds to open the dispute and close it. A couple of cents on each successful transaction should more than cover the cost of that time and it is, after all, just another business expense that should be factored in. I don't get many of them but I certainly don't take them personally and I don't let them occupy my thoughts and time.