Recruit a Friend Issue

Hi, I sent my co-worker a recruitment code amount a month ago, he purchased the game and put the code in after setting up his service account, On the mob station his account stated that he had used a recruitment code, my account also stated you have someone invited using this service code,

He just purchased a 90 day subscription when his trial ended yesterday and none of us have received any of the recruitment code benefits nor have our mob stations changed at all, would love some further information on this.