He DID detain me by preventing me continue with my shopping by blocking
my shopping trolley and proceeding thereafter to the checkout for payment.
It's at this juncture that I insisted that store manager be called.
OK, but he didn't physically detain you or otherwise conduct an illegal restraint as you have alleged above?
Pretty sure all shops have the right to refuse to serve people for no reason at all, as long as it's not on the grounds of race, sexuality or gender.
I just think you're blowing this out of all proportion.