over billing my account

Telkom is over charging me and is irritating is its not the first time and they are billing taking the money in my account before the date we agreed on firstly in November they took the money on the 24th and I'm only getting paid on the 25th obviously they wont get anything in my account because our agreement is the 25th so I called them wanting to know why they deducted on the 24th they told me about if the 25th is on a weekend the take the money on a Friday so they suspended my line just imagine I have 3 contracts with them December they deducted R391 on the 15 Dec 2017 and R860.94 on the 22 December I was ok with it so this month Jan 2018 I get my statement saying I must pay R1520.94 for what I don't know I called them again on the 09 Jan 2018 and asked why am I billed so much the guy said because the R860.94 wasn't received last month the only amount reflecting is the R391 he advised me to get a statement I have sent the statement to the and remember the bank is also charging me for the statement if the system only updates after 7 days of payment why are they send wrong statement if ever they take that amount in my account I will take this matter to the next level I must say I wont upgrade any of my devices due to bad billing services I get from them I need my account to be fixed before end of business today otherwise I'm taking the matter to my legal department and sue Telkom.