Equita notice of inforcement

[Luba]

We have received a notice of inforcement from Equita today, 20 Aug 2015, for driving on bus lane on 16 March 2015. It was a first time we knew anything about bus lane charges. We moved house on 2 March 2015, notified DVLA and council for council tax. Baillifs wants money by 25 Aug 2015. We are most definitely prepared to challenge the notice as we never knew about the charge, do not believe council did not get the letters back because we have bank accounts with tesco and barclays and letters from old address were returned back so banks have contacted us. Also my husband's dad passed away yesterday, really not the best time to deal with bailiffs, especially if we did nothing wrong.

Any advises would be much appreciated.

Thank you