ContributionsMost RecentMost LikesSolutionsRe: Tmobile costco rebate - timeline ? The costco rebate card thing is ridiculous. They say it takes 90 days from the day you activate your lines. And then another 2 weeks for processing from that point. So, almost 3.5 months to get the rebate. Re: Costco offer for BOGO not honored I am having the same problem, did you get this addressed? It has been 3 months and they are not applying the promo.