They deducting in middle of month while my contract states end of the month

They deducted money last day of the month which was correct but then they tried deducting in middle of the month again because according to them they deducted the wrong amount making it my issue so now I got charged insufficient funds because they deducted in middle of month then that amount went off again but now I'm getting court case messages from them although I sended them proof that the money was deducted from my account,at the shop they also showed me they deducting 3 insurances but I only have 2, also they should be deducting 2100 but now they deducting 2358 and because they trying to deduct in middle of month while my contract states end of month now they messing up my credit score also so very unsatisfied.