I'm a broker and find AIB quiote efficient. Have you got the formal loan offer from AIB yet? If so, there will be a few conditions on it that you have to fulfil before AIB will release the mortgage cheque, e.g. life assurance policy, property insurance, Direct Debit Mandate etc. Have you done all of these?
I'd suggest that you ring your solicitor tomorrow to see if s/he has sent all the legal documents and cheque request to AIB. Your solicitor may know why the funds haven't been released yet.
If not, ring AIB or your broker if you're using one. They should be able to tell you where you are.