I have posted before about finances. I work part time, but currently am now working a total of 40 hours a week.more or less because now have another job on top of my current one and now the child tax credit has been reduced this is despite dd still being at college. i did ring but they just put me through to child benefit and he was so nice i didnt feel able to question any further.
Has it reduced because your hours have increased or because they think DD is a non dependent. If it's the latter, tell them she is still in college and they will reinstate. If the former then it is hard, but you are putting yourself in a better position by working more hours, especially as it would be cut soon with DD growing up anyway.
I'd need more information to be able to help, really. If you are working 40 hours per week, you will get a reduction in tax credits because your income will be higher. HMRC get direct info about your wages from your employer.
If your DD is in college and the child benefit agency haven't realised, you may need to confirm that she's in continuing education. Are you still getting child benefit? If not, you won't get Child Tax Credits. That's easy to fix.