prison calls

Yes you should receive prison calls. My best friend whom of which also has T-Mobile receives about 10-15 calls a day from her child's father, sometimes even as late as 9:30pm. She does not put money on his account herself as she has no interest in chit chatting with him so he calls her with money someone else has placed on the account. If you have the scam shield app, turn it off and/ or manually add the phone number to the list of approved callers. Double check that your phone does not have "filter unknown callers" enabled. Make sure the contact is saved. Make sure the phone number is not blocked in your contact list. Other trouble shooting methods after all of that is done and the issue persists is to just simply go into the store (a corporate location because it truly does  make a drastic difference customer service quality wise compared to a third-party retailer)(also observe the representative and see if they even seem knowledgeable and willing to help) because it much easier than speaking to customer service. When you are in the store ask the representative if they can check your features. Have them check the line you are specifically having an issue with for any scam blocking SOC codes. You also probably want to make sure your rate plan supports collect calls. Plans such as the $10 T-Mobile connect prepaid plan will not. 
If you have an android don’t let someone persuade you into getting an issue specifically due to this issue because the type of phone you have is likely not the cause.