I assume this was an enhanced DBS check and the additional information (that you have been charged with an offence) was disclosed by the Police? Unfortunately they are allowed to do this is they determine it is proportionate and hide behind the argument that it is up to the employer to decide whether to employ someone, based on all the available information. Of course, we know that the vast majority of employers run a mile when they see a criminal conviction or even an allegation, where they decide arbitrarily that they won't risk their reputation just in case something went wrong.
A basic or standard check only discloses details of convictions, not charges not yet heard in court.
There was a court case recently relating to a taxi driver found not guilty of rape but the charge information appearing on his enhanced DBS check. He went to court to argue it was disproportionate to disclose as he was found not guilty - he lost the case.