Can you tell me when you made the withdrawal please.
Leave this with me while I draft my answer.
You don't necessarily have to inform HMRC of your pension withdrawal as they will be informed by the pension payer in any event.
However, you may be due a repayment of some of the tax deducted from the pension payment and that will depend on what other income you have in the 2016/17 tax year. Take a look at the notes on pension withdrawal here. As you accessed your pension under the flexibility rules, you should complete a P53Z and sent it to the address at the bottom of the form. This will enable HMRC to assess your tax position in advance of the end of the tax year and make any repayment of tax to you if you have overpaid so that you don't have to wait until after 5 April 2017.
I hope this helps but let me know if you have any further questions.