Telkom apps faulty

I have been informed to use the Telkom apps which I have as I do not receive my Telkom invoice via email, some months is comes and others not. My apps states what I must pay and as my history shows its always paid even extra to round off number. May month Telkom app gave me an incorrect total. I had paid in the amount the apps stated, my account was suspended saying I was short R360. I was so surprised as the app gave me the amount. I was then penalized for R202 on R360 which was not even my fault. Your apps is faulty and I do not get my invoice every month. I will "not pay this out rages fee" for something I did not do. With things in the country now and many battling to make ends meet, be reasonable and make sure your apps and invoices are correct. Check your customers history and see how loyal they have been all these years before you impose such penalties when your apps is faulty. Most annoyed.