Vodacom is Arogant after Upgate and just took my Data that i Paid for.

Hallo, my Data Sim card was due for an Upgrade, so I went to Vodacom Shop in Vanderbijlpark. Liza Helped me. I ask her if i can take a lower Conctract because as she can see on the system i dont use all of the Data that i get everymonth. so she said Yes i can Down grade my Contract, an i Ask her will i Lose the Data 128GB that is left on my Cotract, and she said no... so i downgrade my Contract to a cheaper plan. The Nest day i saw that all of my GB data is Gone and there is only 19.95GB left. So i ask Reino what is going on here Liza said i would not lose it. i said he will find out the Monday, so Tuesday i Phoned me and said Vodacom will give me only 20GB back, and i said no I Paid for all the Previous GB Data and i want all of it back... I paid for it AFTERALL. So Reino said he will ask Liza to sort it out, she phoned me and said she will speak to vodacom, she said she understood me wrong when i ask her if i will lose all of my GB Data... can you believe this, what is there to understand wrong... so she came back to me and said that Vodacom will give me 30 GB back, when i said No she started to get snotty with me and said, well if i don't want to accept this then i will not get anything back. i only said to her that i will speak to Jaco... i did send Jaco a Message on whatsapp, he didn't reply so i phoned him and he said they are very bussy he will ask liza to Phone me. Jaco said that Vodacom did give me 50 GB back, But when i look this morning there was no Data added. I still wait for Liza to call me Back. Vodacom is very Fast to steel our Data that we have Paid for then they will tell me they will do me a Favour to give me some of the Data back that i Paid for.. and if I don't want to settle then I will get Nothing Back.... can you Believe this... Well This is Unacceptable..... even if i don't use all my Data every month I want the Data that i paid for....