Overly tall hedges not being maintained by landlord

Our landlord, Sovereign Network Group (https://www.sng.org.uk/ ) have had this reported to them but I felt it was worth contacting SODC too. As far as I understand it, as they are the landowner (these hedges sit outside of the property boundaries) and we pay a service charge to them every month, they are responsible for maintenance. These hedges will desperately need cutting back AFTER nesting season is complete. Some residents have taken this into their own hands, however as we pay a service charge monthly I feel it is their responsibility as landowner and landlord to ensure that this hedge is trimmed down to a safer, more suitable height as it is currently 6 meters plus in places. Thank you