Account handed over unfairly

I got an sms a couple of days ago that says my account was handed over to an external vendor claiming that my account is 80+ overdue. I admit my account is overdue however it's not enirely my fault. two months ago SB VAF submitted 2 debits, apprx 4112 and 2180. the problem is my balance on the account is about 4200(a debit of 2180 + another 2180 which was a late payment). The debit bounces as there wasn't enuff funds for the 2 transaction. I feel like SB VAF should take some responsibilty in this billing debuckle and they had no right to hand over my account as they also played a hand. I have transfered the balance of account and I hope thats where this ends.