Delhivery — Welcome kit from my company RBS service

My company has provided me a welcome kit it consist pen diary mug sipper and mobile stand and this shipment was going to take on 15th march and on the app of delhivery its saying it has been delivered but i haven't receive my shipment its been more than 5 6 days and i have raised more than 4 tickets but they are just delaying more and more and there are no actions taken by the team of delhivery. and now i want to raise a complaint against them i want my shipment as soon as possible