Kani & Wilken Dobermans Shelby & Ken Williams , Lynndon Bais Won't refund my money for a Doberman puppy returned to them ! wichita Kansas

I bought a show puppy from these people and after a month I found out it had a severe heart murmur. I returned it under the health guarantee that came with the puppy. And they said they would mail the refund to me within 30 days. Well that has been over a year ago. Now they won't return my calls or letters. I messed up and didn't get anything in writing for my return. I just trusted them , I mean , like  , they are at all the shows and are supossed to be legitimate. I guess they are honest after all. I hope this keeps other people from making the same mistake I did. Don't deal with these xxxholes !