Block phone

Sim swap was done, and the number got hacked, got one huge account and was reported to ***** department,, I pay my account every month by Internet payment,, and today my phone was blocked,, this is going on for 3 months now, customer service can't sort it out,, what can I do to solve this problem,, I have all the documents that I have sent them this far, unable to get someone to help,, phoning doesn't help at all,