Southwest Credit Fraudulent Collection Agency - Picks people at random and sends bills with no information not given Texas

I received a bill today from Southwest Credit. There is no return address. There is a demand to immediately pay $200. Not a word about who this is for, what this is for, who the creditor is, - nothing - Nor is there a phone number to speak to anyone there. They did not follow the Fair Credit Reporting Act by sending validation of the debt within 5 days, hence nullifying their claim right there. Yet based on many other reviews they will now attack my good credit. Their behavior is fraudulent, illegal and intolerable. They will now hear from my attorney and I will do everything legal in my power to harm them for hurting so many innocent people. Watch out for these frauds. They are also known for leaving bad reports on your credit after tricking you into paying them by saying they will have it removed. They are in Carrollton, Texas, 4120 International Pkwy #1100.