To thank a customer, you should say:

A、Thankyouforcomplaining,itmakesmydaygobyfaster.;
B、Thankyouforbringingthistoourattention.;
C、Thankyouformakingproblemsforus.;
D、Thankyouforbotheringme,ithasbeenaninconveniencespeakingwithyou.