Billing issue for 5 month straight... Fed up!

Rain.... For 5 months I've been trying for you to update my payment date from the 20th of every month to the 1st of every month. Because your sales guy selected the wrong payment date when i signed up. 5 months later every month on the 20th my service get suspended. I call the call senter... I get informed that they will escalate it to billing department but I need to pay half of my monthly instalment for them to reconnect me. The i do that and then i get confirmation over email that the payment date have been updated... Just to get to the 20th of next month to have my service suspended again... 5 months later and last week on the 20th I got hold of an awesome guy in the call senter saw on my profile that this has been a ongoing thing... He got me in touch with the team leader phoned me back everytime he told me he would. The team leader got hold of billing department and my service was reinstated in 1 hour and it was confirmed that the billing issue is sorted. Just for today to come... And for Rain to suspend my service again... Guess what same issue... Call the call senter... Get the phoned put down in my ear 2 times... 4 agents telling me they will escalate the matter to billing department and consider it a urgent matter... And they will give me call updates every hour... Guess what... Nothing NADDDDDA.... No one is getting back to me... 5 houers later still no internet... One guy even put me me on hold to supposedly speak to a team leader... For 40 minutes... And again no team leader... I'm fed up... Im over this... After 5 months struggling with this issue... I'm now done... Rain can take their internet and flyyyyy....