Staff promoting false information

I'm so disappointed, Yesterday I went to Steers Gateway for a quick lunch after work, as I started to eat my meal I was approached by one of the cashiers who **** to me and said they have discounts going on for regular clients, so she'll like to get my number and name so that will send info on when the specials are on and or rewards type of a thing.... So because I normally buy from them I was like okay sure, I gave in my number and name I didn't mind since I saw she's working there she can't be fooling me... Only to find out that today I'm getting a whatsapp message from a guy who says he's working in steers gateway he's sorry he had to take my number like that!!! I feel this is totally unacceptable for the staff to be promoting something that's not even there to customers. I'm so disappointed in both of them for misleading me as a loyal customer to Steers and getting my details for wrong reasons.