overpayment of discretionary housing benefit.

Housing Benefit Overpayment

Hello,
I have been sent an invoice and reminders to repay discretionary housing benefit for a tenant I receive direct payments for.

The letters say she had a change in circumstances. I have asked Leeds City Council for an explanation of why it it recoverable from me instead of the tenant and the only reply I gat was because one of their staff said so, yet I can have no knowledge of the changes in circumstances of tenants. what can I do about this. I am at the end of my tether with this tenant as she is £3,000 + in arrears with rent. If I end up having to pay this out I will end the tenancy as nothing is worth having to deal with the council.