***** by Woolworth groblersdal mall

i have been paying my account every month, last week when i went to pay for the month of may i was told that my last payment was in February. now i asked them what happened to they money that i have been paying for march and April? the store manager told me that because i am old maybe i have forgotten to make payment for those month and yet i have proof that i have payed. my account is now in arrears. this is reflecting bad on my. words cannot describe how i feel right now, i called the head office their system still says my last payment was in February. where is my money? does Woolworths treat old people like this?