Use of Past Perfect

Hello...

There have been some controversies on the use of “had agreed” in the passages below.

Some people think this is wrong and ungrammatical.

Others think this is perfectly correct use of Past Perfect.

I wonder what the Gurus here might think of this.

To make it clear, I post the full context, before and after.

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My mother has long realized the limitations of her English as well.

When I was fifteen, she used to have me call people on the phone to

pretend I was she. In this guise, I was forced to ask for information or

even to complain and yell at people who had been rude to her. One time

it was a call to her stockbroker in New York. She had cashed out her

small portfolio and it just so happened we were going to go to New York

the next week, our very first trip outside California. I had to get on the

phone and say in an adolescent voice that was not very convincing, "This

is Mrs. Tan."

And my mother was standing in the back whispering loudly, "Why he

don't send me check, already two weeks late. So mad he lie to me, losing

me money."

And then I said in perfect English, "Yes, I'm getting rather concerned.

You had agreed to send the check two weeks ago, but it hasn't arrived ."

Then she began to talk more loudly. "What he want, I come to New

York tell him front of his boss, you cheating me?" And I was trying to calm

her down, make her be quiet, while telling the stockbroker, "I can't tolerate

any more excuses. If I don't receive the check immediately, I am going to

have to speak to your manager when I'm in New York next week." And

sure enough, the following week there we were in front of this astonished

stockbroker, and I was sitting there red-faced and quiet, and my mother, the

real Mrs. Tan, was shouting at his boss in her impeccable broken English.