Customer service and MTNSA service provider,Mondo

i took a 80gig data contract with MTN.(50g day time & 30g night).The MTN is debiting my bank account for this contract but what they are actually giving me is 20 g day time and 10g night data. This has been going on from August 2020.Yet they deduct the whole amount. When i contacted them on the 12th September 2020,they reply with an apology and a reference number, then keep quiet. When i contact them ,they repeat the act. I have about 4 different reference numbers for the same query. I am frustrated to the core. I don't know where to go seeing that their customer service did what i explained above.I tried their Customer complaints department who promised to get this matter sorted but weeks have passed and no help.Their marketing agent,Mondo,is as just as useless as them.Consumer/Customer is not taken seriously ,judging by the way they handle my complaint.How else can one explain an email from the company you are complaining about,saying we HOPE your query has been sorted.I am yet to see such a pathetic customer service from any RSA company.