I'm afraid a severed fibre optic is not an easy fix. Your only course of action is to take multiple pictures of the shoddy work and contact openreach support stating just how disgusted you are with the quality of installation , the negative impact it has had on your business productivity and your mental health. Hopefully an emergency repair can be arranged ASAP , but make sure you stress to them the utter inconvenience caused by their incompetence and sheer unprofessional behaviour. Good luck, give em hell
