Ex husband told kids Santa didn’t come

How do I address this? He moved out in November, we have been separated two years however. He had 2x weekly visitation, and every other weekend before he moved - he would visit my house because he couldn’t have the kids where he currently lived.Now that he moved out l, he got the kids Xmas morning, which is fine. He has been hurting for money since he moved out, and told me he couldn’t afford presents. I explicitly told him I would buy presents to be from SANTA. I have him them Xmas eve, along with stockings and stocking stuffers for our children.I ask him when he is dropping them off, and he said “I didn’t realize I was”. I have told him 4x that the plan is he gets them overnight (ie Xmas morning) and I get them in the afternoon. He says fine, he isn’t feeling well anyways.He drops them off and after he leaves kids tell me Santa forgot them. They got lots of toys, and are happy with Xmas but I can’t stand the fact that they think Santa forgot them. How can I fix this? I am so mad at my ex for taking the presents I provided from Santa and claiming them as his own. So mad. via /r/Parenting http://bit.ly/2EPyfHg