not receiving short code messages

I was a sprint customer originally then once t mobile and sprint merged i was told i needed to get a t mobile sim card or i would no longer have service on my device, so i went to the store and got one. Ever since i put the card in i have not received any short code messages meaning i cant verify changes to my credit card, authenticate/verify accounts linked to my phone number, or get any sort of information about upcoming appointments from businesses. ive talked to a few different people over the phone, i made contact with the “T-Mobile help” account on twitter where i was given the same solution by two different people for a totally different phone manufacturer than i was using. I really dont want to change providers but the way things are going it seems like im not getting any sort of help here and my time is being wasted.