Makro RCS app authentication failed

Hi. I cannot get the Makro RCS app to work. It keeps saying : Authentication failed. This happens every now and then. It just stops working for weeks on end. Then it suddenly works again for a few weeks. I reinstalled the Makro rcs app, restarted my phone, cleared cashe, deleted Truecaller months ago (yes i know all the silly questions you ask as I deal with this every few weeks). Call centre don't respond to my emails or online chat. I have no way to check my balance or outstanding amount. Kindly fix this ******* app. (Android, Samsung Galaxy S22)