Confusion complaint

Well I have a credit card with the blue bank standard bank and all was well... Payments and all was going well when I was with the bank, left the bank for personal reasons, continued paying my CC... Even had my wife doing her part... Next thing I'm called by MBD collections company... My cc had been handed over... To my shock cause I thought one is handed over when they not making payments.. Rejected MBD idea cause I felt was still in good books with my CC ...and this is maybe son company taking chances...I admit my mistake was rebelling cause I eventually didnt know what was up, stopped paying everything ... Next thing I'm getting threatening emails, I'm in debt in arrears and all the negatives u can think off... Cause standard bank failed to communicate with me mind u I have made means to pay what I owe them yet I found myself having to deal with people I don't even know, I mean whos comfortable with paying some company they don't know in SA nowadays... Very dissapointed.. Now am in arrears they say and owe them ...