The deserving poor by Mary Haylet

My first post what do you think of this poem? what do you think it's literary purpose is?

The deserving poor

I am I am I am
the deserving poor.
Bring you cast off clothing
to my door.
Thank you thank you thank you
you’re so pure,
you help to keep us going
like manure.
Old dressing tables, bed spreads,
carpets on the fade.
CD players on the blink
we’ve really got it made.
They don’t know how I manage.
They don’t know who I am.
They just know I am grateful
so they couldn’t give a damn.
We don’t refuse a single thing
who knows what might turn up
some rubies in the rubbish
some tea leaves in a cup.
And we should be so lucky
and sorting is such fun
and it’s bound to come in handy
ammunition for my gun.
I am I am I am
the deserving poor.
God help the ones that aren’t
that’s for sure
so thank you thank you thank you
you’re my friend.
We’ll get it sorted
In the end.

Mary Haylet