*****ing airtime/data add additional charges and never have signal

I have used MTN since the beginning of MTN. But the last 12 months have been terrible and it just gets worse, I never have signal. I can't use zoom meetings due to this my data and airtime disappear ALL the time, the call centre always ask for the number and will get back to you, they never do and then a day later you sit with R200 extra charges this is ridiculous