Very poor service from MTN staff

I'm a student and during this lockdown period we have online classes. These online classes used up all of our data on our router. We tried various ways of recharging and none was successful. I contacted an agent and she was unable to help me. Then I sent two emails in which I asked them to help me because I'm a student and need data, they did not reply to any of my communication attempts. I am really unhappy with MTN and their poor service.