2 calls logged closed without any feedback

At the end of September, I logged a call asking for specifics on an exorbitant bill I received on my data stick. I provided them with all the data required, only to find out, when I called back the following week, that the call was closed due to insufficient data been sent through to the back office. Another call was opened with the promises of me receiving a call or email with regards to my query within the same day. Once again a week later and still nothing. I called once again this morning, to be told that the call has once again been closed. CellC is very quick to bring you on board as a customer but when it comes to actually providing service.....it is non existent. I am not sure how else I can get the data I requested as I can not get further than the call centre operators. I am seriously considering breaking contract with them as they have not lived up to their part of the contract by providing me with the service I deserve. The call centre operators I have spoken to are embarrassed by what is happening and they can also only escalate this to the back office and hope and pray it gets resolved. Chantel Jooste, please do your job and provide me with the data I require