Stumped on this difficult Array Problem: Anyone willing to see if they can solve

I am trying to solve this problem using array, where I don't have to input formula input in every cell. I am basically trying to consolidate the data into sales $ for customers by month. I can solve this problem relatively easily by using pivot tables. But i really want to solve this problem using array. I've been at this for hrs. But can't seem to figure it out.

Please help Excel MASTERS!!!

Excel file is attached. Also see copy and pasted data below.

CUSTOMER Jan Feb Mar Apr May Jun
A
B
C
D
E
F
G
H
I
J



Dates Sales Customer Month
4/16/2013 $691 A Apr
4/12/2013 $6,382 A Apr
1/26/2013 $4,648 A Jan
6/1/2013 $3,618 A Jun
3/11/2013 $4,191 A Mar
3/15/2013 $8,492 A Mar
5/23/2013 $1,734 A May
4/25/2013 $2,748 B Apr
4/8/2013 $9,738 B Apr
1/18/2013 $2,084 B Jan
3/20/2013 $9,285 B Mar
3/22/2013 $9,313 B Mar
3/30/2013 $7,418 B Mar
3/4/2013 $7,085 B Mar
2/11/2013 $5,655 C Feb
2/28/2013 $3,158 C Feb
1/7/2013 $5,403 C Jan
1/28/2013 $2,526 C Jan
3/17/2013 $3,423 C Mar
5/3/2013 $7,652 C May
5/25/2013 $6,287 C May
4/11/2013 $2,149 D Apr
4/24/2013 $6,344 D Apr
2/8/2013 $4,691 D Feb
1/25/2013 $5,044 D Jan
1/22/2013 $3,809 D Jan
1/21/2013 $8,634 D Jan
1/20/2013 $9,074 D Jan
1/2/2013 $5,107 D Jan
1/11/2013 $5,373 D Jan
3/10/2013 $6,232 D Mar
5/15/2013 $8,260 D May
5/12/2013 $8,523 D May
5/30/2013 $5,100 D May
5/4/2013 $6,889 D May
2/26/2013 $6,366 E Feb
1/20/2013 $7,643 E Jan
1/16/2013 $6,759 E Jan
1/24/2013 $9,843 E Jan
3/22/2013 $8,432 E Mar
3/6/2013 $8,953 E Mar
5/9/2013 $7,056 E May
5/28/2013 $9,977 E May
5/28/2013 $3,267 E May
5/25/2013 $2,299 E May
5/7/2013 $9,630 E May
4/27/2013 $3,643 F Apr
4/28/2013 $5,425 F Apr
4/5/2013 $5,710 F Apr
2/19/2013 $4,533 F Feb
2/15/2013 $641 F Feb
2/25/2013 $3,577 F Feb
2/20/2013 $1,062 F Feb
1/25/2013 $1,806 F Jan
1/31/2013 $8,519 F Jan
1/11/2013 $9,538 F Jan
6/1/2013 $2,324 F Jun
3/21/2013 $5,356 F Mar
3/19/2013 $6,236 F Mar
3/28/2013 $5,108 F Mar
5/20/2013 $1,835 F May
4/11/2013 $7,858 G Apr
2/8/2013 $3,680 G Feb
2/18/2013 $4,255 G Feb
1/12/2013 $821 G Jan
5/19/2013 $3,755 G May
5/12/2013 $5,013 G May
5/2/2013 $6,826 G May
2/16/2013 $4,335 H Feb
2/25/2013 $7,793 H Feb
2/7/2013 $4,253 H Feb
1/5/2013 $8,101 H Jan
1/30/2013 $9,810 H Jan
1/5/2013 $917 H Jan
1/12/2013 $6,917 H Jan
3/8/2013 $7,896 H Mar
3/13/2013 $1,692 H Mar
5/26/2013 $5,054 H May
5/6/2013 $2,993 H May
4/18/2013 $4,247 I Apr
4/20/2013 $1,613 I Apr
2/7/2013 $4,791 I Feb
2/6/2013 $1,397 I Feb
2/21/2013 $2,648 I Feb
1/17/2013 $3,711 I Jan
3/30/2013 $8,349 I Mar
5/8/2013 $9,860 I May
4/15/2013 $2,495 J Apr
4/3/2013 $7,071 J Apr
2/9/2013 $8,207 J Feb
2/1/2013 $6,799 J Feb
2/4/2013 $6,833 J Feb
2/28/2013 $2,875 J Feb
1/12/2013 $704 J Jan
1/27/2013 $2,692 J Jan
1/23/2013 $6,267 J Jan
1/7/2013 $7,868 J Jan
1/26/2013 $6,060 J Jan
5/24/2013 $558 J May
5/23/2013 $9,287 J May

Seems to partly work. But for some reason the May Sales column comes to all 0's, which is not right.