I still don’t know what exactly is your issue, but if your complain is about call centre availability, then a lawyer specializing in business contracts may be able to help you, as call centre service may be treated as part of the contract. A lawyer specializing in consumer rights may work too. But to be clear, I am not providing any legal advice here.
However the first thing they would ask, is to let you document the call centre wait time.
The moment you really look into litigation, you will want to step out of it.