(1) We hope you will pardon us for troubling you.
(2) We regret the trouble we are causing you.
(3) I regret the trouble it caused you.
(4) We trust you will excuse us for this inconvenience.
(5) We wish to crave your kind forbearance for this trouble.
(6) We solicit your forbearance for such an annoyance.
(7) Kindly excuse me for troubling you in this metter.