Anyone experiencing delays in receiving their Child Tax Credit/Working Tax Credit should contact their MP's office as they have access to a Tax Credit hotline. Explain that you are experiencing financial hardship and despite submitting your application however many weeks ago have heard nothing.
When calling the Tax Credit Helpline they will just give you the runaround and say your application has not been given an award yet and has not met the timescales to be processed.
However when someone from your MP's office contacts them on the MP's hotline they will quickly find your application and process within a week or so.
I have found out through my own experience that this is the only way I could find to get my application looked at after waiting four weeks after returning the application.
HM Revenue and Tax Credit office is in near meltdown and experiencing long delays in dealing with applications as they are inundated with claims.