Unresolved trade in credits

It’s been past 2 months have not gotten my phone credits was supposed to get 1,100. Have called multiple times have opened multiple tickets still no resolution in sight. All I want is what was promised when I switched over to Xfinity. So far feels like you guys just took my phone and gave me nothing. I have provided IMEI numbers. Tracking info that you guys sent me label for. Not sure what else I can do to get my credits.