Incredibly bad customer service

Middle March 2020 I app**** online for data contract 40Gb night 40GB day, in the second week of April 2020 the simcard was delivered at my house, the delivery guy explained that the simcard is activated and that I must insert the simcard in my cellphone and wait a few hours. The next day there was still no network on the simcard, a week later still no network. I struggled for more then a month sending emails to get it activated, I came across a support whatsapp number which didn't work, I made phone calls to customer care from someone else's mtn number to get the simcard activated still no luck. There was no number for the simcard when I received it. So since I have received the simcard I was never able to use it and now after four/five months Mtn sends me email and sms to make payment for the simcard that was never used.