problems with phone trees?

Having problems with the "phone trees" for businesses. My iPhone has no problem MAKING phone calls/dialing a number, but I tried to call my health insurance, and it makes you type in things like your birth date, but when I use the dial pad to type in the date, it doesn't register that I typed anything in. I ended up having to speak all the info to get to a person. Tried to call my banks, but neither bank's phone system would register any input, one bank, just kept hanging up. I COULD NOT get through because it just kept repeating the same thing asking me to put in my ID number for them and hit pound (and I did) but it acted like I had done nothing. Same with the other bank. I have an iPhone 6, with the latest update, no other problems, and am using T-Mobile. Is this a problem with my phone, and if so what could be causing the discrepancy between making phone calls, and registering input during a phone call? If it's not a problem with my phone, could this be a problem with my carrier? Any input at all would be so appreciated, I'm so frustrated right now at not being able to get ahold of a live person for my own stupid bank accounts 😟