Why have I still not received my HST cheque?

I filed my taxes one or two days late, and received my income tax return towards the end of May. I still have not received my HST cheque, and I do not understand why. Everyone else I know, including those who filed up to two weeks later than I, have received their's. Who do I call about this? The only number I have been given is to an automated voice service that tells me nothing about the HST cheque, only the GST. Anyone know any numbers? Or why I may not have received my HST cheque yet?