unexplained charges.

i took out a vodacom open line data contract in January. it was agreed that i was going to pay 129 per month. in July and august i ran out of data but since i knew that my contract was an open line i did not have any stress. The problem is when i tried to connect to the internet it didn't want to connect telling me about being offline. To my surprise i was charged extra. when i went to inquire in store i was told that it was the out of bundle rates. i then gave them my device so that they can see for themselves that i was unable to connect to the internet without data even though it was a open plan. After realizing that it was not working they changed their stories and told me that it was because i was making calls on that devices. o told them that it was impossible because i have never tried to make a call on that device. we then tried to make a call but it didn't work. on the September i was charged 3000. when i went to inquire at the store they couldn't explained as to how that money escalated to that amount. i then called their finance department and was told that my querry will be investigated and will get response within 7-14 days. To date i am still waiting for an explanations and my lines have since been suspended. i have decided to cancel the debit order until this matter is resolved.