Bad customer service

From May I had a problem viewing my statements and invoices, I visited the Newtown Junction branch and they told me it might be a problem with the phone am using, I then forwarded the email to my work email but I still couldn't open my invoices and statements, I went back to the branch and they called the call centre and they also didnt know why, all this time am going there am being told that my account is up to date I dont need to worry. The problem persisted and I called MTN and I was told this will be rectified this is after I sent an email to advise that I cant open my statements and invoices. I got a shock on the 29/12/2015 when I got an sms saying that I owe MTN an amount of R58.85 when I called the call centre I was advised that the rates were increased in May and that sms's were apparently sent to clients were as on my side I never received that sms. I then sent emails to the complaints department were as to date I still have not received any feedback, am being sent sms's almost on a daily basis regarding this outstanding amount but I have not been told about the rate increase, and now they suspended my line with out any feedback on the emails I sent to MTN. Please rectify