From what I've read Magnum Z is also known as Debt Doctors. If that's the case here is their contact info:
Debt Doctors
P O Box 126
Wentzville, MO ÂÂ*63385
Telephone: (88

276-4189
I found this for Whisler Holdings:
Xpresscash
2207 Concord Pike #505
Wilmington, DE 19803
800-757-0122
option 1 is for loans
option 2 is for collections
option 3 is for customer service (who told me they were related to Whistler-Holding)
Other numbers on the BBB site are
800-351-8820 and 800-493-3380.
and their wesbite is xpresscash.com/
I'm sure it's purely coincedence (note my sarcasm) but AIP's address is:
AIP
2207 Concord Pike
Wilmington, DE 19803
I'm thinking they are the same company, or at least related.
There are multiple addresses for United Cash, I don't know if they are all the same company or not.
United Cash Loans
3531 P Street NW
Miami, OK ÂÂ*74355
Telephone: (800) 230-9480
Pinion Management dba United Cash
2730 San Pedro Dr NE Ste H Albuquerque, NM 87110
Primary Phone:
(800) 430-5024
United Cash Loans
2533 N. Carson St Ste. 5020
Carson City, NV ÂÂ*89706
Telephone: (800) 354-0602
Fax: (88

570-9772
Ameriloans addresses match exactly to the above for United Cash Loans, so they are also the same company.
For Route 66 here's some of the addresses:
Route 66 Funding
46 State Street
3rd Floor
Albany NY 12207
1-877-564-7738
1-877-564-7739
1-877-646-9618
fax 1-877-564-7740
Route 66 Funding
1005 Terminal Way STE 102
Reno, NV ÂÂ*89502-2179
Telephone: (877) 564-7738
Fax: (187) 756-4774 ext. 0
The last two, Electronic Pay and Midland Market I can't find anything about. I will keep looking and see if I can find anything about them.