NES operates multiple contracts across the UK. Each may be structured slightly differently. Typical structures may include a Team Leader, reporting to an Area Manager, reporting to the Operations Director. Out of Hours a duty Manager will be allocated. In addition, there is an administrative office team supporting you in the field.
What is crucial, is that you know who you directly report to, and that communication follows the structure in place. All requests for holiday, reporting sickness / absence etc should follow the reporting structure. Never be afraid to escalate serious issues when required or when people in your reporting chain are absent but always try to follow the management structure in place.