upgrade gone wrong

I upgraded to data only deal with a mothly suscription of 199.00 and i was to receive 500mb data every month. the first debited amount on the 28 Agust was 113.00. the next debit was on the 28 August which was 459. i called the call center and they guy i spoke to could not give me clarity on to why that amount was debited insted of the agreed 199.00. i gave them my email address and i asked for a statement 'they promised to send but even now i am still waiting. i went to reverse that amount and they called and told me my line will be suspended when i ask why they debited that much they said that is what i used for the month because i am on a open plan. i disputed and told them that i took a top up. i asked for the recording of the sale ,i was given a reference number and told to wait for 2 days. i called them after 3 days seeing that they dont call me. they said my issue is not attended yet. i am surprised why are they not attending to that but they suspended my phone. they even went to debit my account again, please help without resolving the issue