I'm not sure where you are based but, for example, in the UK i'm using VOXI which is part of the Vodafone network.
My number is with Telynx and I'm unable to text it from my phone because Vodafone see it as a chargeable number outside of my inclusive SMS. They tested this by giving me £1 credit and I sent a text fine. Try another network to see if you are able to get through.