I cannot add a line or upgrade my mobile phone - No one at comcast business cares

This is infuriating. I have been with comcast business for 4 years with respect to business internet. I signed up for mobile as well in November with a single line and brought my own phone. I am now unable to add a line or upgrade my phone because apparently comcast never ran my credit so its showing I have zero available. I have spoken to 10 different people at comcast. No one has been able to address this issue despite promising to do so. Its embarrassing. The only reason why I am staying with comcast mobile is that there is a $40 dollar credit promo for the first year. After than I am gone. The is no customer service here. With Verizon and T-mobile 5g business internet available I am looking into switch my internet service as well.