Straight Talk Straighttalk StraightTalk customer service non-existant. Won't refund for returned card almost $50 bucks! Miami, Florida

Bought a StraightTalk phone from Walmart and returned it within the hour. It came with a card to activate the phone and I was told by Walmart that although they could refund the phone, they could not refund the card. I sent it to StraightTalk by certified mail, which USPS shows was received on April 19th. I have been trying to call them but can not get through to a live person. The recording even skips and starts all over again like a broken record. They have the Zero key, which is normally reserved for an Operator, set up to "repeat the menu". I contacted my credit card company and they even tried to get through without results. But, because the charge was made to Walmart and not StraightTalk, my credit card company can't do anything about it because they can not take the money from Walmart (since technically- the card belongs to StraightTalk). StraightTalk is probably aware of this and is why they don't feel they need to return my $50 dollars or answer the phone. Beware of StraightTalk! If you ever need them, you will not be able to get in touch with them. Plus, they just ripped me off of $50!