i got a text from this number 818-292-9478 saying i won a 900 gift card for walmart

I received a call, caller id showed Phoenix, AR (480-543-1329). Rep. with strong accent stated that I had been selected to receive $125 Gas card and $600 Grocery and she wanted my card number just to verify that I was the authorized card holder and she wanted the expiration date. Her company would be mailing out the cards that I had won free, only with a $5.95 shipping fee that needed to be charged to my card the day after I was going to receive the free cards. She needed to make sure that the logos matched and needed to know if it was VISA or MC. When I refused to give her any numbers she said that her supervisor could explain it better. Then a man with even more of an accent told me that his name was Love Williams and that his id number was 1104 and that his company is in collerabtion with VISA & MC to give away these free cards to the customers that already have cards and use them at Walmart and the grocery stores and gas stations. I refused to give him my card numbers, he started to get upset. I then told him that I wanted his number to call him back once I thought about it. He didn't give me a number but hung up instead. Please do not give your numbers out to any one and please be careful of scams like this.

I just got a call from a 10000000000 number and it sounded like an Indian guy. He said i won a 100 dollar wal mart gift card and all i had to was verify my information and pay 2.95 when i received the gift cart. When I asked him why i was receiving the card, he said because i have done a lot of shopping at wal mart in the last six months, i only use cash at wal mart so there would be no way for him know this information. He asked me if * was my name, which it was, and asked me if * was my address, which it was, and then asked me to give him my sixteen digit card number and i told him i didnt want to do it. He insisted that those numbers were not chargeable numbers, they just verified my name and address. I told him that i know those numbers are chargeable because i work at a business and when credit cards are damaged and wont swipe, we use the sixteen digit number as well as the expiration date. He again assured me that i wont be charged again and i hung up. He tried to call back again and i did not answer. I tried to call them back, just to see and of course i couldn't call that number back, .. How did the get my fist and last name, address, and cell phone number????? Should i be worried