Failing to provide service for long existing customers

After being a loyal customer for several years, I am currently want change networks thanks to Vodacoms extremely poor customer service. My problem is as follows: My debit order was always on the 26th of every month, due to a friend using the contract number and paying the contract I moved the debit order date in one of the vodacom's outlets to a date they provided as available dates for debit orders. I chose the 7th of every month, the consultant failed to inform me, by doing this the debit order will move earlier instead of later. So the debit order came back and I was penalised with R100 for that. I contacted the customer care department and spoke to managers, but all they answer is that is how our system work when I ask(request and complain that I recieved statements and invoices late). The debit order is on the 7th but I only recieve the invoice and statement after the 11th sometimes even after the 15th of a month. They generate invoices on the 3rd of every month and back dates the invoices to the 1st, and no one can provide me with a valid reason for this. Also when I upgraded the same contract recently they activated the new additional line but physically canceling the upgrade for the main line which I had to return to the store and re-do everything just to get billed doubled for the activation of the new line, the consultant logged te query with them to credit the new invoice for the activation,until now it is still not resolved or any feedback regarding it provided.