Out of stock for months

I have been waiting for months for a turqoise cover for Sony Z3 Compact to come available on the online store. Today I get a notification that it is now available. I proceed to the website and purchase my turqoise<br> cover. Only after I have made the payment I get an email to say that it is yet again out of stock and not available after I have waited months for this product they just never have stock available. Unacceptable! Dont avertise stock that you do not have. Will definitely never again be purchasing from your online store!