Bad service

I pay my account every month on the last day of each month the date I get paid. I had credit available last week and today I wanted to order and my credit is on zero. This is the second time this happens and it takes forever to fix. Can you please stop blocking me for being a good payer that only gets paid on the very last day of the month and I always pay the exact amount that you say I have to as soon as my pay comes into my account. Your finance department call me all the time asking when is my next payment date. Can you please mark it clearly and stop calling me as I do pay.