Very bad service

I have been with rain for some time now, my payment date was always on the 25th which was paid every month. A few days ago I changed it to the 1st, their system said payment will still go off on the 25th and going forward from the 1st. But since the 15th of March they cut off my service. I've called their call centre 3 times and I get no help what's so ever besides I must make payment. I've never experience such bad service with regards to a simple change of payment date . If my last payment was on the 25th how you can ask for another payment on the 15th, that is absolutely ridiculous, I strongly suggest anyone with the network not to change their payment date or you will have same problem, and trust me their call centre is waste of time, they take all your details and nobody gets back you or they tell you it's their system and they can't do anything.