They said they have no record of this. It’s my word against theirs. when I phoned them up to let them know about changes they said they already knew. They use real time reporting now apparently so they see my income changes as soon as it happens how the hell does an overpayment happen?

After some advice here folks. Last August HB contacted me saying I had been over paid to the sum of £700, Down to the fact changes in tax credits, changes in tax code etc and I didn't notify them. I admit I didn't, it was my own fault and so my housing benefit was getting reduced to repay the overpayment, lesson learned, notify them of everything. So imagine my surprise when the exact same thing happened again this August, another overpayment for £400. I did notify them of everything this time. I disputed this, I gave them times and dates when I called in to notify them but they were not interested. When my money wasn't in last week I phoned to inquire why, they told me a pack of lies, saying it was a system error, nothing to worry about, payment will be in the next payment run. The next day in comes the overpayment letter. I put it bluntly to them any issues was down to whoever answers there phones, they are totally incompetent, not down to me, I played my part, I notified them and even gave them times and dates after searching my phone records, they would neither confirm or deny it was there fault. I have also put this in writing but I suspect it won't matter who is in the wrong it will still be my fault and i'll have to repay it. Is there anything else I can do?