False advertising

I baought an I phone from Mtn in February 2024 the phone came with R230 airtime and once off 10 gig data .i did not receive 10 gig once off data . I tried contacting Mtn .they said they will investigate and come back to me .I waited for 2 months.i didn’t get it after 2 months.i text them to ask them about the investigation and submitted proof that I never used nor received data on that SIM card. They said I can go to the store to activate the data . Mtn evaton mall staff said they don’t deal with online contact .I contacted Mtn again they said they are still investigating 7 months later im still inquiring about data that was falsely advertised