unknown

I have an account with homechoice, I had a debit order arrangement with them, month end November when the debit order was supposed to go through it didn't so I got a call from one of their agents that I need to pay, we then made another debit order arrangement for the 7th of December, the debit order also didn't go through to them according to them, but money was deducted from my account, and when I checked my statement it says debit order reversed. then they tried again to debit on the 9th and on the 16th, but with no luck as there were no funds in my account. Now they are saying I need to pay R1300 while the message I got from them on the 14th of December says I need to pay R873.6. I need to know why the R1308.00 on their system?