Vodacom at *******ion

Hi Vodacom is ripping me off. They called me to take the Contract with and I took it so in my contract it says I will Pay R175 per month for 24 months they gave me Huawei Y5 blue so every month I make sure that the money is available for them to debit but 2 months ago they tried to debit on the 23rd where else my contract says on the 25th of every month so now when I went to my Vodacom app it says I still owe R100.80 I called the customer service on and they told me that it arrears I asked them how is it arrears because I paid them they said the money was not on the account on the 25th I get paid in the 24 at night the money is always there but they said it was not there so I ended up paying for myself because they debit the money late so when I called them again they said my problem is with my bank now they saying I'm owing R466 for arrears but I pay every month please help as I like to pay for my contract but I feel like Vodacom is ripping me off.

Thanks