I use a ATT app for security. Your cell provider should have one thats free though added features may cost more. I dont block numbers anymore because it doesnt help. I ended up with a blocked number list a mile long and the spam calls and texts still kept coming. With the security app turned on, it blocks about 50-70% of them.I've blocked calls without any issues . . . how are you blocking the messages?
Bottom line there is only so much even security apps can do. I dont answer calls or texts I dont recognize. If they call and dont leave a message, its spam. If a text doesn't have the company name in the text, it gets deleted