Delivery companies place fake attempts to process RTO

Delivery company Xpressbees placed fake remarks in 2-3 shipments while talking rudely to the customer. i have customer recordings to testify my issue. For every Return to Origin they earn extra money from the shipper and this leads us to a huge loss. I am in a lot of mental agony as I escalated these issues multiple times to the shipping aggregator and delivery companies, but they sit on the complaints and just provide auto generated responses till RTO gets notified after which they close the complaint (Shiprocket). Please let me know the best possible route to take now