DATA ISSUE

I have been a customer of MTN for more than 10 years. 8 years on contract. Since March I have been experiencing data issues. I emailed mtn and it's just a back and forth thing. One Time I'm being told that it's the network towers in the area the next time I'm being told it's my data that's actually is the problem. I sent over 50 emails to MTN and till this date the issue is not resolved. They can not explain to me how 20gbs of data is being used in a space of 2 weeks for only whatsapp and Facebook. I have Fibre at home and use the fibre most of the time. Absolutely disgusted with this service. To treat a loyal customer in this manner absolutely pathetic