False adverti*****t

I have an R5 milk voucher that I wanted to use today but in the end, I could not and am very unhappy about it. say R5 for any long-life milk. The manager informed me then I could not use it on the product that I bought. If the the voucher says ANY it means any otherwise it is a false adverti*****t. You must specify what the word ANY means at Woolworths.