Failed to terminate account and reverse charges

Neotel overcharged me in June / July by charging over the limit of an uncapped account resulting in a failed debit order. Then when I wanted to make an online payment for the correct amount the credit card function did not work giving a java io error, since then I have had sever conversations with neotel staff to have this resolved with no luck at all so I requested cancellation of the account if the funds are not reversed that was overcharged yet no one contacted me back again. I then did the same by Phone, Neotel admitted to the overcharge and I have a recording of this but still no reversal took place and my account was not terminated as requested until last month, and now I'm being harassed for money that should not be owing if reversals where done from the first cancellation request. I also had to pay the failed debit order fees and my credit record has been impacted. The staff at the Neotel store's are also not trained properly and it took two hours to figure out they provided me with the wrong password for the device.