Keeps calling, Omni Credit Union

This says Omni Credit Union but it's one of those "your auto warranty has expired calls."

Called and told me that my 2007 Buick warranty has expired....I DO NOT OWN a buick!
SCAM!

please do not call

This is over the 20th call from this number, I do not recognize so I never answer. When I call back it say it "can not be connected as dialed" What should I do next. These people are costing me money. This should be stopped. Point me in the right direction. jffhll3@gmail