Payflex are ************* ****s

I'm so ****ed and disappointed. I assigned a date of the month that payflex is supposed to take money from my account. For the 1st payment they took the money on the specified date. The 2nd payment went off on a random date not agreed on. They didn't fond any fund available and charged me a fee for an unsuccessful payment. I have been writing to them since and no one has bothered to respond to me. They eventually found funds in my account at a random date that is not one agreed on as the salary date on the app is the 15th. They still charged me a fee for late collection. They usually prompt to respond but now because they did ******* they are not bothering to respond to me. I'm very angry.