Internet service cut due to debit order date not available on mtn system

I have the home starter internet wifi bundle that I use for work. Since the beginning mtn could not change the debit order date to the 25th. Today they have cut my internet and Im only getting paid in two days. Why do this to a loyal customer. Now I cant work and will loose money. Why cant you system take my debit date as the 25. Im furious.