Tire Sidewall problems of the 2001 Toyota Tundra

Low mileage, two year old front tires beginning to separate at inner sidewalls, making vibrations above 50+ mph and shaking vehicle so bad almost undriveable at highway speeds. Alignment shop said get them checked. Re-balancing tires had no effect, moved front tires to rear then bed of truck would vibrate at speed. Replace the 2 tires in question and problem resolved. Had tire shop look at the tires and they found tread separation at inner sidewalls of both suspect tires. Called manufactured for warranty replacement or refund and they needed a rma form filled out by an authorized dealer who sells this brand of tire before a return could be accepted. Original purchase was online from walmart for pickup at local store. Walmart had no record of the tire seller who supplied online walmart sales. Manufacturer referred me to a 'discount tire' store locally that manufacturer had previous contact with and dealt in this brand of tire. Contacted the suggested store and salesman needed to contact manufacturer first to know how to proceed. After a callback from store, salesman tried to diagnosis the tire problem over the phone without actually looking at the tires and said tires were probably out of round. I have the two tires and still pondering for a solution.