Can anybody help with these sentences

We are sorry to hear that our staff are said to have intentionally bothered your activity at our school yesterday. After thorough investigation, we trust that your accusation is invalid as our staff just tried to ask your colleagues to provide the approval letter but was ignored by them without explanation. Similarly, much garbage was found being left at our school after your activity, which is now pending for your clearance. Please take prompt action to submit the approval letter and clear the rubbish by tomorrow to assure us you are still a responsible applicant for using our facilities in future.