Mr price saying out of stock while stock is available in store.

I am not happ with what Mr price just did to my order I made a purchase for boots online there was stock now out of 7 boots they say 5 boots are out of stock but at the stores there are sizes how is that so that all sizes are out of stock while shops have stock of the same sizes. Other people received their full orders why is mine changed to out of stock when I made order there was still stock