Fnb *****ing from clients and ignore queries

Every month for the last 4 months my data just miraculously disappears from my fnb connect SIM card, every time I call in the agents tell me it's internet usage and when I explain that my phone has no automatic updates or background apps running and that it only happens between 830pm and 6am they tell me they Will log the query and someone will contact me.... NOBODY EVER DOES! On Friday 02/03/2018 the same problem occurred, I called in and once again the same story, but this time I was told by a team leader that someone will definitely contact me the very next day, and NOBODY did. I've been calling in everyday since, so that's Friday, Saturday, Sunday, Monday Tuesday and today Wednesday and I still have no answers. Now during all these calls and they have been many, I've had agents cut my call 3 times when I asked to speak to a manager, I've had a rude agent, I've had agent tell me that the team leader I spoke to Friday misled me by saying I'd be contacted on Saturday. Now today when I call in I get told that there are no managers in the call centre. I cannot be getting ****** like this by FNB on a constant basis and NOBODY from fnb is interested in attending to my query. Is this the manner in which fnb treats it's clients?