not so much a deal as advice for people who have been overpaid tax credits ( there are thousands of us apparently). I was quite happy to have my overpayments repaid to the taxman from future tax year credits until I received an annual renewal where it stated I did not have to pay the overpayments back if it was an error by the tax office. I submitted a claim as it was their mistake, two other people from my workplace that I know of had the same error, namely salary = £0, which generated the initial overpayments.
Tax office admitted liability and wrote off the overpayments, however I had received no tax credits for 4 years. I have since contested this and claimed tax credits for this 4 year period and they have just paid out to me!
What a result, if anyone would like advice if in same situation feel free to pm me.