Midwest All Perennial Wildflower Seed Mix

Not as expected-

I bought the Midwest all perennial wildflower seed mix and planted this spring. I am excited as my bare plot of dirt is growing, not many flowers yet which is perfectly acceptable. I’m NOT happy bc my flower mix had tall grass seeds mixed in. I dod not want any grasses in my flower bed! And there is a lot! Not just a few stragglers. I’m worried they will take over my flower bed in the next couple years as the abundance is great already 🙁 super disappointed and unsure what to do about it.