Just got the same thing.
They claim to be in partnership with Alamo.
They do a hard sell and try to get you to give up your credit card number

Hi, whoever calls this number beware! These scumbag scammers are using the fact that Ebays help number which is 866-540-3229 is similar to the number they have taken out of 800-540-3229. If you accidentally dial 800 instead of 866 for this number you will end up with someone saying they are doing a promotion of Caribbean Cruises through Ebay and are trying to get your money and credit card information. Do not fall for it. These people are a disease to the rest of mankind which is struggling to make ends meet. Ruthless b*****ds ... I hope they get caught and are put in jail where they belong. AL