Wrong Medication

I went last week Friday to buy a flu ****tail at Shoprite jan smuts in kempton park at medi-rite pharmacy fast forward I take the medication assuming it’s flu ****tail which I should get better within a day or two cause that’s how effective the medication is when you take it for flu however up to today am still sick only to realize that it’s not flu ****tail that was given to me it is actually Gout ****tail now I am suffering the effects of the medication and I would like to sue them for giving me the wrong medication