Disappearing Airtime

I've been a loyal Vodacom client for more than 15 years now but lately I've been considering moving to a different network due to constant airtime loss. I used to get messages when my data is almost finished but lately I don't get any resulting in my airtime being used without warning or any knowledge. I've complained to through the contact centre 3 times. The second time I was given complementary 1G data for a month. However today it's even worse because my airtime was used even though I had data and the problem of not getting data usage sms notifications has still not been solved.I called the customer service centre and spoke to Thuso Komane who told me it's my fault because the data network in my area got disconnected therefore my phone automatically used my airtime instead. I don't understand how this can be my fault as I do not provide data network... Vodacom does. My problem has not been solved and I'd appreciate it if I get my airtime back.