All round poor service

I change my bank details. The payjustnow app would not accept my new card. I emailed them, with no response to date, I tried using the chat bot, which turned out to be so useless. I called them, and when I get infront of the que, I get disconnected. Someone from best buy tyres helped me add my new card, and by then payjustnow added almost R400 in interest. If they were just there as a customer support service, I would not have to pay the additional fees as I wanted to pay them on time. Even now, it's the next month already, and yet to still here from my email response even. Very poor service all round