Unfair Charges

Although I am grateful for being given some time off from paying for my car, I am extremely unhappy with the service I am now receiving from MFC. When I was given a break, I received a document that read the next debit would be on 25/02/2020 but there was no amount to be debited. I made sure I had the normal amount of money for my car before that date so that they could debit but they did not debit. I contacted the bank to check why they did not debit and the lady I spoke with said it was delayed but it will be debited. I then asked her how much am I supposed to pay and she said X amount. On 26/02/2020, I receive an email from the bank with a letter of demand accusing me of not paying and I sent them an email asking why I'm getting the letter when it was their fault they did not debit. They never rep**** to the email. Today (27/02/2020), I get a call from them asking me why I didn't pay and I told her that it isn't my fault. It's then who didn't debit my account and she couldn't make sense of it. I asked her how much should be debited and she said Y amount. I told her that yesterday, I was told that it's X amount and today, she says it's Y and ask why. She said it's the charges from being served with a LOD. I told her that it's the bank that didn't debit. The money was in my account so that the debit order can go through. She said she didn't understand and will escalate. I'm not happy at all with how this is being treated. First you tell me I have to pay X amount then you say I have to Y amount because I didn't pay X amount when X amount was already in my account ready to be debited?? No man. That's bull.