R4700 worth of data ****** and billed into my account

i have been an excellent customer of vodacom for close to 20 years ,i was hit with a R4700 bill for using data out of bundle, i get messaged that I'm about to run out of data bundle and then i purchase data by dialing *111# they then confirm that my purchase was successful and i got back on the internet but they kept messaging that i was still going under the last i saw was 2000rand under although i had purchased data. I'm very upset!!!