Pittsburgh Hotels in Oakland

I booked through Kayak at the Hilton Garden Inn in Oakland Pittsburgh for a Business Trip. I specifically picked this hotel because it was the location of several business meetings, and I had several meetings in walking distance. However, once I arrived, I was told that my booking was independently changed to the Hilton Garden Inn in Downtown Pittsburgh. While it's only three miles away, that would require me to spend a lot of time in a cab between meetings, and incur additional cab costs. I did not have time to travel back and forth with my business schedule. I told the Amoma this, cancelled my booking with them, and booked a new hotel on my own next door, the Hampton Inn in Oakland. I have still not received a refund, and now Amoma is asking me for bank statements to prove I booked a new hotel. This whole experience is unacceptable. I expect to be refunded in full, and I'm tired of dealing with Amoma and their booking problems.