Blocking SMS Short Code Texts From Third-Party Service I Paid For

I am a mobile Notary Public and signed up for a services to help me scheduling my appointments. This service works by sending text messages to me providing appointment details and URL links .  Unfortunately, T-Mobile has been blocking their text messages during the past year and the service reports that they have other T-Mobile clients that have had their messages unblocked and I should contact T-Mobile to have this fixed.  This has caused me to lose thousands of dollars in services I provide and has given me a bad reputation for not responding to appointments with these other companies. I see that you've unblocked others. Would you please unblock SMS short codes from third-party services to my account as well? Every day this is costing me more money.