$ Had come is wrong because it places one action in the past before another action in the past —
not the meaning expressed by this sentence. Instead, sentence one needs a verb to link past
and present, and has come fills the bill.
% Will be places the action in the future, but the memo once again seeks to establish that the
bending went on in the past and continues in the present, so present perfect tense (have been
bending) does the job.
^ Bent is an irregular past form. Bended is never correct in standard English.
& Because you’re talking about duty, should works nicely here. You may also select am reminding
because the boss is in the process of reminding the employees of paper clip prices.