Sonic Drive-In

I ordered a vanilla and chocolate shake on September 30, 2019. They were gritty like sand in them. I have been a customer for several years this is the first time I have had a complaint about your shakes. I will continue to go to Sonic because the customer service is very good the food is always good. I just wanted to let you know so you are aware so you can fix the issue. Thank you for your time in this matter. I hope you have a blessed day.