How does the Father get his child from DHS if mother was arrested?

A little over a year ago my ex(common law married in Alabama: papers signed and everything) took my daughter to Oklahoma to visit her parents and had a round trip plane ticket but did not come back. 2 months later she came back to get her things and did not bring my daughter. I tried calling to police dept, but all they could tell me was to get a lawyer and I could not afford one. I had a phone number but she refused to give me an address and would never answer the phone but would call me for money. So about a month ago my ex was arrested in Oklahoma for manufacturing and distributing meth and had our daughter in the house. When she was taken to jail social services took my child and never notified me of anything. Apparently she told them she didn't know how to get in touch with me at all which was a lie. I found out what happened from my ex's sister and contacted DHS immediately. Now I have to go through a process which may take 6 months or more to get my daughter back but they told me had she given them my info they would have contacted me to come pick her up and bring her back home with me immediately. I have all the paperwork birth cert/social sec/hospital records/common law marriage papers and EVERYTHING but I am being treated as if I was never in the picture at all. I have a court date next week and I am driving to Oklahoma from Alabama for this which is a long drive and expensive and I will also have to take off work to do so. I have been in touch with the social worker and the foster parents and they have even let me video chat with my daughter. But why is this such a process? I have been trying to get my daughter back with me for over a year now and SHOULD have been contacted immediately when my ex was arrested. I am at a loss and have no idea what to do now. I should have been informed to just come pick my daughter up but now that she has gone into foster care they wont let me take her. What should I do and why are they doing this to me? I have absolutely no criminal background and have a very nice house with my daughters stuff still here and everything. Shouldn't they just release her to me? Please if anyone could help me I would be very grateful!