Not Receiving Group Text Responses from Verizon Customers

After 90 minutes on the phone with AT&T Technical Support, I'm told that the reason I'm not receiving group text message responses from Verizon customers, is because Verizon is blocking my number. I don't really understand this because I can receive individual texts from Verizon customers. The solution is that I tell my friends who use Verizon to call their carrier and request my number not be blocked. Are you kidding me?!?! They said it's a known issue, so why isn't AT&T stepping in and calling Verizon to resolve this? This is ridiculous! Unfortunately, dropping AT&T won't fix the issue because it's Verizon's fault, or so they say. Maybe it's time for a new cell phone number AND carrier... I'd really appreciate someone at AT&T reaching out to me so I can provide information so that AT&T can call Verizon and get this fixed. This is horrible that AT&T isn't doing anything on behalf of their customers and instead pointing the finger at Verizon. You mean to tell me that you don't have a liason to help resolve your customer's issues that involve other carriers? You're going to lose a customer over this if it's not resolved without my friends having to waste their time relaying to Verizon the issue I'm having with my phone.