Home Office contact number

My visa application was approved on 21st September. In my application I had mentioned that my office address is my correspondence address and I also confirmed it with my case worker that my BRP should be delivered to my office address and she said it would be. But I think DX (the courier company) still attempted to deliver it at my home address and left a missed delivery card as nobody was home during office hours(9am to 6pm). They are not allowing me to change the delivery address or deliver the BRP before 9am or after 6pm or anytime on weekends, that is the only time I can be home to collect it. The DX office is really far from where I stay so I cannot even go to the office to pick it up and their office isn't open on weekends.
I want to contact the home office so that they can amend the address , but I am unable to find any contact information (telephone number). I have already sent an email to BRPDelivery@homeoffice.gsi.gov.uk, but there turnaround time is 5 days, and I am kind of in a rush at the moment. Does anybody have a telephone number where I can get in touch with home office ?

This is the number for applicants: 08706067766
I just called them and spent 10 minutes on hold.