***** upgrade

I took a 24 moths contract with vodacom in 2014 were I wa s paying R50 for 500mb data I never canceled the contract wen it ended because I was happy with the data that I was getting. On 2018-05_31 I was shocked when I check my balance it was sitting at 0.0 on 2018-06-01 i checked my balance again to see is they have returned my data and also loaded as it was a new months the balance showed me 0.0 data i was credited with airtime . i contacted the call centre i spoke to penelope who told me that i upgraded my contract which i never did wen i asked her how the cotract was upgraded she didnt have an answer she placed me on hold for 30 minutes while contacting the ***** deparment tha never picked up the phone . i was adviced to send a copy of my id and 3 signatures to ********** which i did on the 1 of june .on the 11 i contacted customer service to do a follow up i spoke to nwabisa who gave me their ***** department contact number ********** 530 which no body bordered to answer .on 2018-06-09 a recive an invoice stating that an amount of R749 will be debited on my account which i never aggred for . on 2018-06-14 i contacted ustome service i spoke to lindiwe who transferd me to charles who was very rude the told me that he work from 8 to 16:00 . I need is answers I want to know who upgraded the contract and how was it done as I have never requested for an upgrade. ***** ref. Ec-1jgg1852q and ec-1j19u069