Confused about billing amount

I tried reaching out via Facebook and I sent an email to customer care. Up until today, my query is not resolved. Mondo rep**** requestimg me to log the query online and follow the link submit query in email. Submit query tab is not active. On Facebook an automative response confirmed I need to contact service provider the contact number which is provided does not take me to a consultant. I still don't know why I'm paying r399. 00 for 20gigs day and night. The sales agent confirmed it will be r99 and it will commence end August 2022. But the deduction of r399. 00 for 20 gigs deduction went through end July 2022. Mondo don't care about the client after the sale was concluded.