Chancers

I would like to tell the people out there about this company,i have had a woolworths visa card about 15 years ago,i lost my job that time and could not pay my account,i did let woolworths know i am unemployed at that time,so they never send me a statement again,about 2 years ago out of the blue i got a call at work from this company MBD,i told the lady that this debt is older than 10 years and should have been written off long time ago already,she told me that day that she can see it is a very old account and will take it off immediately,its now about 4 months or longer they sending me emails again stating that i owe them money on this woolworths card,i will NOT pay it as that debt is very old and should have been written off long time ago already,i want to know how i can report them and to who,watch out people this company are taking chances and want people to pay for old debt.