Abi
Not credit for return empty bottles

I have an account ABI that supplies beverages since this this year January I have enquiring, setting meeting with
Accounts department to sort lots of discrepancies that are in my account, They have been blocking my account
And telling me that that I owe them which was not true

they sent sent me a statement with balance of R 3008 when I asked them how did it get there which invoices were not paid
I did not get answer then I requested the spreadsheet where they record my payment and I discovered that I was not credited for the returned empty bottles and crates which cost R 41.58 each quanties of 29 total amount of R 1420 for the invoice of 14 November 2012
They were so much mistakes that they were in my account thanks to lady called Busi Sibisi who corrected some of them

Now dropped to R2353.00 but still this R 1420 not yet credited to me so now I am obliged to this before the 20th of this month otherwise
I can not be able to do business with them. I only owe them the invoice of this year may which is R 1116