How about using a free 3rd party service? For example, blockchain.info has their free API to receive payments.
Just posting here for the information ->
Blockchain.info does not allow the full API access to gambling websites ,which is true in OP's case.
->Blockchain.info rejects all the remote procedure calls from unknown sources (as per their recent update)
->You may be tracked if you are given the full api access through the secret key.They would know the exact amounts deposited through your addresses.
->Due to following security issues,I'd not advise anyone to use their API for commercial business.Write your procedures from scratch.