Looking for some advice on how to deal with this problem I'm having
with Cingular.

Back in April, I went to a Cingular reseller store and purchased a
phone and a plan.  After figuring out that the phone didn't get good
reception where I needed it (a military base), I returned it within two
weeks and expected to get a full refund of the phone (around $82).

The woman I returned it too was the same one who sold it to me, and
since she was busy with other customers, I just gave her the phone and
she said she'd take care of it for me and the refund should be on my
credit card in a few weeks.  I never received a confirmation number or
any sort of paperwork indicating that I actually returned the phone (my
fault).

Cut to almost 5 months later.  The store I purchased it from is now an
official Cingular store.  Previously, they were under a different name,
but only sold Cingular phones.  Anyway, I've been in contact with the
store manager on almost a weekly basis, and he conviently forgets who I
am and what I'm calling about, and I give him my information every time
I talk to him, not to mention never calls me back when he says he will.
Nice guy, but totally useless to me.

I'm really looking to escalate this to the next level, but not sure
where to start.  I called the Cingular customer service number, and
they said that I needed to work it through the local store I purchased
it from.  My only idea at this point is to somehow find out who
actually owns the store, and see if I can get them to cut my refund.
In my mind, all they need to do is verify that they have (or have
re-sold) the phone I returned (based on the serial number) and then cut
me a check... right?

Has anyone tackled a problem like this before?  I've seen other posts
saying to go through the credit card company, but since it was charged
over 5 months ago, is there anything they could even do at this point?

Appreciate any tips or information anyone could give.